Spring Constant Calculator: Hooke's Law, Force, and Deflection
Calculate spring constant (stiffness), spring force, and deflection using Hooke's Law. Covers series and parallel spring combinations and natural frequency of spring-mass systems.
Blog
211 expert guides on calculators, conversions, science, finance, and more
Showing 211 guides
No guides in this category yet
Check back soon — new guides are added regularly.
Kinetic Energy Calculator: Mass, Velocity, and KE Formula
Calculate kinetic energy from mass and velocity using KE = ½mv². Covers units, worked examples for vehicles and projectiles, and the relationship between speed and energy.
Potential Energy Calculator: Gravitational and Elastic Potential Energy
Calculate gravitational potential energy (mgh) and elastic potential energy (½kx²). Understand energy conservation and how potential energy converts to kinetic energy.
Wave Frequency Calculator: Frequency, Wavelength, and Wave Speed
Calculate wave frequency, wavelength, and wave speed using the wave equation v = fλ. Covers sound waves, electromagnetic waves, and the electromagnetic spectrum.
Ideal Gas Law Calculator: Pressure, Volume, Temperature, and Moles
Calculate any gas property using the Ideal Gas Law PV = nRT. Covers Boyle's Law, Charles's Law, Gay-Lussac's Law, and worked chemistry and physics examples.
Electrical Resistance Calculator: Series, Parallel, and Temperature Effects
Calculate equivalent resistance for series and parallel resistor networks, find temperature coefficient effects, and understand resistivity vs resistance in conductors.
Projectile Motion Calculator: Range, Height, and Flight Time
Calculate projectile range, maximum height, and flight time from launch angle and initial velocity. Includes the effect of gravity, worked examples, and optimal launch angle.
Gravitational Force Calculator: Newton's Law of Universal Gravitation
Calculate gravitational force between two masses using Newton's universal law. Covers surface gravity, orbital mechanics, escape velocity, and gravitational acceleration on other planets.
Electric Field Calculator: Coulomb's Law and Field Strength
Calculate electric field strength, electrostatic force between charges, and electric potential using Coulomb's Law. Covers point charges, field lines, and worked physics examples.
Molar Mass Calculator: Molecular Weight and Mole Calculations
Calculate molar mass of chemical compounds from atomic masses, convert between mass and moles, and find the number of molecules using Avogadro's number.
Photon Energy Calculator: Wavelength, Frequency, and eV
Calculate photon energy from wavelength or frequency using E = hf and E = hc/λ. Convert between Joules and electron-volts, and understand applications in optics and quantum physics.
Buoyancy Calculator: Archimedes' Principle and Floating Objects
Calculate buoyant force using Archimedes' Principle. Determine whether an object will float or sink, find displaced fluid volume, and understand density relationships.
Concentration Calculator: Molarity, Molality, and Dilution
Calculate solution concentration as molarity (mol/L), molality (mol/kg), and percentage. Use the dilution formula C₁V₁ = C₂V₂ for lab dilutions.
Half-Life Calculator: Radioactive Decay and Exponential Decay
Calculate remaining quantity after radioactive decay using half-life formula. Find the half-life from decay constant, and apply exponential decay to physics, chemistry, and pharmacokinetics.
NPV Calculator: Net Present Value and Discounted Cash Flow
Calculate Net Present Value (NPV) and IRR for investment decisions using discounted cash flow analysis. Understand when to accept or reject projects based on NPV rule.
Standard Deviation Calculator: Population and Sample Variance
Calculate standard deviation and variance for a dataset. Understand the difference between population σ and sample s, and when each applies in statistics.
Z-Score Calculator: Standard Normal Distribution and Percentiles
Calculate z-scores to find how many standard deviations a value is from the mean. Convert z-scores to percentiles and probabilities using the standard normal distribution.
Linear Regression Calculator: Slope, Intercept, and R²
Calculate linear regression line (y = mx + b), slope, y-intercept, and R-squared coefficient of determination. Understand how well the line fits your data.
Probability Calculator: Basic, Conditional, and Bayes' Theorem
Calculate event probabilities including independent events, conditional probability, and Bayes' Theorem. Covers the addition rule, multiplication rule, and complement rule with worked examples.
Lens Calculator: Focal Length, Magnification, and Image Distance
Calculate focal length, image distance, and magnification for converging and diverging lenses using the thin lens equation. Covers real vs virtual images and ray diagrams.
Decibel Calculator: Sound Level, dB Conversions, and Hearing Safety
Calculate sound levels in decibels (dB), convert between power and intensity ratios, combine multiple sound sources, and understand safe noise exposure limits.
pH Calculator: Acid-Base Chemistry and Hydrogen Ion Concentration
Calculate pH from hydrogen ion concentration [H⁺], find [H⁺] from pH, and understand the acid-base scale. Covers pOH, pKa, buffer solutions, and strong vs weak acids.
Normal Distribution Calculator: Mean, Sigma, and Probability Areas
Calculate probabilities and percentile ranges for normal distributions. Find P(X < x), P(a < X < b), and use the empirical rule (68-95-99.7) for bell curve problems.
Confidence Interval Calculator: Margin of Error and Sample Size
Calculate confidence intervals for a population mean or proportion. Find the margin of error, determine required sample size, and interpret what a 95% CI actually means.
Black-Scholes Calculator: Option Pricing and Greeks
Calculate European option prices using the Black-Scholes model. Find call and put prices, understand the inputs (volatility, strike, time), and interpret Delta, Gamma, and Theta.
Correlation Coefficient Calculator: Pearson r and Interpretation
Calculate Pearson's correlation coefficient r between two variables. Interpret r values from +1 to -1, test for significance, and understand the difference between correlation and causation.
Calorie Burn Calculator: Exercise, MET Values, and Weight Loss
Calculate calories burned during exercise using MET values and body weight. Estimate how long you need to exercise to create a calorie deficit for weight loss.
Age Calculator: Exact Age in Years, Months, and Days
Calculate your exact age in years, months, and days from your birth date. Find age difference between two dates and determine upcoming milestone birthdays.
Date Difference Calculator: Days, Weeks, and Months Between Dates
Calculate the exact number of days, weeks, or months between any two dates. Find business days between dates, exclude weekends, and plan project timelines.
Time Zone Converter: Convert Time Between Cities and UTC Offsets
Convert time between any two time zones instantly. Understand UTC offsets, Daylight Saving Time transitions, and how to schedule meetings across international time zones.
Sleep Cycle Calculator: Best Bedtime and Wake-Up Times
Calculate the best time to go to bed or wake up based on 90-minute sleep cycles. Understand sleep stages, how many cycles you need, and why waking between cycles feels better.
GPA Calculator: Cumulative GPA, Grade Points, and Credit Hours
Calculate your GPA from course grades and credit hours. Find weighted GPA, cumulative GPA, and what grades you need to hit a target GPA.
Currency Exchange Guide: How Exchange Rates Work and How to Get the Best Rate
Understand how currency exchange rates work, why rates differ between banks, cards, and bureaux de change, and how to get the best rate when converting money abroad.
Roman Numerals: Converter & Rules
Free Roman numeral converter: 2024 = MMXXIV · 1999 = MCMXCIX · 2026 = MMXXVI. Covers the 7 symbols, additive and subtractive rules, dates, chapter numbers, and clock faces.
Shoe Size Converter: US, UK, EU, and CM Sizing Charts
Convert shoe sizes between US, UK, European (EU), and centimetre systems for men, women, and children. Includes width fitting guide and how to measure your foot at home.
Clothing Size Converter: US, UK, EU, and Asian Size Charts
Convert clothing sizes between US, UK, European, and Asian sizing systems for men, women, and children. Includes size charts for tops, bottoms, and dresses.
Weather Unit Converter: Temperature, Wind Speed, and Pressure
Convert weather measurements between Celsius, Fahrenheit, Kelvin, km/h, mph, knots, and hPa. Includes common weather forecast values and what they feel like.
Geographic Distance Calculator: Great Circle Distance and Travel Time
Calculate the straight-line distance between any two locations using latitude and longitude (Haversine formula). Estimate travel time by car, plane, or on foot.
Binary to Decimal Converter: Number System Conversions
Convert numbers between binary (base 2), decimal (base 10), hexadecimal (base 16), and octal (base 8). Step-by-step conversion methods with worked examples.
Aspect Ratio Calculator: Screen Resolution and Image Dimensions
Calculate aspect ratio from width and height, resize images while maintaining ratio, and find the equivalent dimensions for common formats like 16:9, 4:3, and 21:9.
Reading Time Calculator: Words Per Minute and Article Length
Calculate how long it takes to read any text based on your reading speed. Find your words per minute (WPM), estimate blog post reading time, and improve reading speed.
Pace Calculator: Running Pace, Speed, and Race Finish Times
Calculate running pace from distance and time, find finish time for 5K, 10K, half marathon, and marathon, and convert between min/km, min/mile, and km/h.
Fuel Efficiency Guide: MPG, L/100km, and Cost Per Mile
Calculate fuel efficiency in MPG or L/100km, estimate fuel cost per trip, and compare vehicles. Includes conversions between US mpg, UK mpg, and metric fuel consumption.
Color Code Converter: HEX, RGB, HSL, and CMYK
Convert color codes between HEX, RGB, HSL, and CMYK formats. Understand when to use each color model and how to pick accessible color combinations.
World Clock: Current Time in Major Cities Around the Globe
Find the current time in any city worldwide. Understand time zone offsets from UTC, Daylight Saving Time rules, and how to quickly convert across time zones for international calls.
Loan Amortization Calculator: Monthly Payments and Payoff Schedule
Build a full loan amortization schedule showing principal and interest breakdown for each payment. Calculate total interest paid over the life of a car loan, personal loan, or mortgage.
Unit Price Calculator: Compare Value and Find the Best Deal
Calculate price per unit (per gram, per litre, per item) to compare different pack sizes. Find the best value when grocery shopping or comparing bulk vs single-unit prices.
Typing Speed Calculator: WPM, CPM, and Accuracy
Calculate your typing speed in words per minute (WPM) and characters per minute (CPM). Understand what affects accuracy and how to improve your typing speed efficiently.
Bra Size Calculator: Band Size, Cup Size, and Sister Sizes
Calculate bra size from band and bust measurements. Understand sister sizes, international bra sizing (US, UK, EU), and how to get the right fit.
Pregnancy Calculator: Due Date, Weeks, and Trimester Guide
Calculate your due date from LMP or conception date, find how many weeks pregnant you are, and understand what happens in each trimester.
Cooking Measurement Converter: Cups, Tablespoons, Ounces, and Grams
Convert cooking measurements between cups, tablespoons, teaspoons, fluid ounces, millilitres, and grams. Includes ingredient-specific weight conversions for flour, sugar, butter, and liquids.
BMI Calculator: What Your Body Mass Index Actually Means
Understand Body Mass Index — the formula, BMI categories, limitations, and how to use it alongside other health metrics.
Calorie Calculator: How Many Calories Do You Actually Need?
Find out your daily calorie needs using the Mifflin-St Jeor equation, activity multipliers, and how to adjust for your goal.
Body Fat Calculator: Measuring and Interpreting Your Body Fat Percentage
Learn how to measure body fat percentage using the US Navy method, skinfold calipers, and what ranges are healthy for men and women.
Water Intake Calculator: How Much Water Should You Drink Daily?
Discover your daily water intake target based on weight, activity, and climate — and why the "8 glasses a day" rule is oversimplified.
Macro Calculator: Setting Your Protein, Carb, and Fat Targets
Learn how to calculate your macronutrient split for fat loss, muscle gain, or maintenance — with practical gram targets per meal.
Heart Rate Zones Calculator: Training Smarter with Target HR Zones
Understand the 5 heart rate training zones, how to find your max heart rate, and which zone to target for fat burning vs. cardio fitness.
Lean Body Mass Calculator: Understanding Your Fat-Free Mass
Find out what lean body mass is, how to calculate it using the Boer and James formulas, and why it matters for protein targets and fitness goals.
Waist-to-Hip Ratio Calculator: A Better Predictor of Health Risk Than BMI
Learn how to measure your waist-to-hip ratio, what the results mean, and why WHR is a stronger predictor of cardiovascular risk than BMI.
Body Surface Area Calculator: Why BSA Matters in Medicine
Learn what body surface area is, the Mosteller and Du Bois formulas, and why BSA is used for drug dosing and burn assessment.
Hydration Calculator: Personalising Your Fluid Intake for Performance
Beyond basic water intake, learn how exercise intensity, sweat rate, electrolytes, and climate affect your personalised hydration needs.
VO2 Max Calculator: Understanding Your Cardiorespiratory Fitness
Find out what VO2 max is, how to estimate it without a lab, what your number means by age and sex, and how to improve it.
Blood Pressure Converter: Reading, Converting, and Understanding Your Numbers
Understand systolic and diastolic pressure, convert between mmHg and kPa, and know exactly what each blood pressure category means.
Blood Sugar Converter: mmol/L to mg/dL and Understanding Glucose Levels
Convert blood glucose between mmol/L and mg/dL, understand fasting vs post-meal targets, and learn what HbA1c means.
Due Date Calculator: Calculating Your Pregnancy Due Date and Milestones
Learn how due dates are calculated from LMP and conception, understand gestational vs embryonic age, and key pregnancy milestones by trimester.
Child Growth Calculator: Tracking Height, Weight, and Percentiles
Understand growth percentiles, the WHO and CDC growth charts, and what it means if your child is above or below average for their age.
BMR Calculator: Your Basal Metabolic Rate and Why It Matters
Understand what Basal Metabolic Rate is, how it differs from TDEE, and which BMR formula — Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle — is most accurate for you.
Ideal Weight Calculator: What Is a Healthy Weight for Your Height?
Compare five different ideal weight formulas — Hamwi, Devine, Robinson, Miller, and BMI-based — and understand which is most appropriate for you.
Calories Burned Calculator: How Exercise Activity Affects Your Energy Expenditure
Use MET values to estimate calories burned during any exercise. See how running, cycling, swimming, and strength training compare per hour.
Protein Intake Calculator: How Much Protein Do You Need Per Day?
Find out the science-based protein requirements for muscle building, fat loss, endurance sport, and healthy ageing — with examples and food sources.
One-Rep Max Calculator: Estimate Your 1RM Without Maximal Testing
Calculate your one-rep max using the Epley, Brzycki, and Lombardi formulas. Use it to set training loads across the full rep range.
Running Pace Calculator: Converting Between Pace, Speed, and Race Finish Times
Convert running pace (min/km or min/mile) to speed (km/h or mph), project finish times, and understand training paces for easy, tempo, and interval runs.
Pregnancy Weight Gain Calculator: Healthy Ranges by Pre-Pregnancy BMI
Learn the IOM recommended weight gain ranges for pregnancy, how weight is distributed across trimesters, and what gaining too much or too little means.
Sleep Calculator: How Many Hours Do You Need and When Should You Sleep?
Find out your optimal sleep duration by age, how sleep cycles affect when to wake up, and the science behind sleep debt and recovery.
TDEE Calculator: Total Daily Energy Expenditure Explained
Understand Total Daily Energy Expenditure — how it differs from BMR, how activity multipliers work, and how to use TDEE for fat loss, muscle gain, or maintenance.
Healthy BMI Range by Age: Is BMI Still a Useful Health Metric in 2026?
Explore BMI ranges for adults and children, how BMI thresholds shift with age, and the emerging evidence that waist-to-height ratio may be a better predictor.
Loan Calculator: Monthly Payment, Total Interest, and Amortisation Explained
Learn how loan payments are calculated, what an amortisation schedule shows, and how interest rate, term, and principal interact to determine your true cost of borrowing.
Compound Interest Calculator: The Formula That Builds Wealth
Understand compound interest, the Rule of 72, and how frequency of compounding affects your returns — with worked examples for savings and investments.
Mortgage Payment Calculator: Monthly Costs, Total Interest, and Affordability
Calculate your monthly mortgage payment, understand fixed vs adjustable rates, and see how a larger down payment or extra monthly payments cut your total cost.
EMI Calculator: Equated Monthly Instalments Explained
Understand how EMI is calculated for home loans, car loans, and personal loans — with the formula, a worked example, and how to reduce your EMI burden.
ROI Calculator: Measuring Return on Investment the Right Way
Calculate ROI, annualised ROI, and understand when ROI is misleading — with comparisons to IRR and how to use ROI for business and investment decisions.
CAGR Calculator: Compound Annual Growth Rate Explained
Understand CAGR, how it differs from average annual return, how to calculate it, and when to use it to compare investments, business growth, or portfolio performance.
VAT Calculator: Adding and Removing VAT from Any Price
Calculate VAT-inclusive and VAT-exclusive prices, understand standard vs reduced rates across countries, and how to reverse-calculate the tax from a gross price.
Discount Calculator: Original Price, Sale Price, and Savings
Calculate sale prices from percentage discounts, find the original price from a discounted amount, and work out profit margins and markups for pricing decisions.
Savings Calculator: How Long Until You Reach Your Goal?
Plan your savings target using future value calculations — whether you're saving with a lump sum, regular contributions, or both.
Tip Calculator: How Much to Tip and How to Split the Bill
Calculate the right tip amount for any service, split a bill evenly or unevenly among a group, and understand tipping norms across different countries.
Profit Margin Calculator: Gross, Net, and Operating Margin Explained
Learn how to calculate gross, operating, and net profit margins — what each measures, how they differ from markup, and benchmarks by industry.
Break-Even Calculator: When Does Your Business Start Making Money?
Calculate your break-even point in units and revenue, understand the contribution margin, and use break-even analysis for pricing and capacity decisions.
Simple Interest Calculator: Formula, Examples, and When It Applies
Understand simple interest — the formula, real-world examples where it applies, and how it compares to compound interest over different time periods.
Present Value Calculator: What Is Future Money Worth Today?
Understand present value, the discount rate, and how to use PV to compare investment options, value cash flows, and make smarter financial decisions.
Inflation Calculator: What Does Your Money Buy Today vs the Past?
Calculate the real purchasing power of money across years, understand CPI, and see how inflation erodes savings — with historical UK and US inflation context.
Mortgage Affordability Calculator: How Much Can You Borrow?
Find out how much mortgage you can afford based on income, expenses, and lending multiples — and understand the stress tests lenders actually apply.
Gross to Net Salary Calculator: Understanding Your Take-Home Pay
Convert gross salary to net take-home pay — understand income tax, national insurance, and deductions across the UK, US, and other tax systems.
Percentage Change Calculator: Increase, Decrease, and Difference
Calculate percentage increase, decrease, and difference — understand when to use each, avoid common mistakes, and apply them to prices, statistics, and business metrics.
Cash Flow Calculator: Tracking Business Income and Expenses
Understand operating, investing, and financing cash flow — how to calculate free cash flow, why profitable businesses can still run out of cash, and what healthy cash flow looks like.
Markup Calculator: Setting Prices Above Cost
Calculate selling price from cost and markup percentage, convert between markup and margin, and avoid the most common pricing mistake that costs businesses thousands.
Payback Period Calculator: How Long Until Your Investment Pays for Itself?
Calculate simple and discounted payback periods for business investments, understand when to use each, and see how payback period fits alongside NPV and IRR.
Rent vs Buy Calculator: The Real Financial Case for Each Option
Compare the true 10-year cost of renting versus buying — including opportunity cost, maintenance, transaction costs, and house price appreciation.
Future Value Calculator: What Will Your Money Be Worth?
Calculate the future value of a lump sum or regular contributions at a given interest rate — and see how inflation, compounding frequency, and time interact.
Sales Tax Calculator: Adding and Removing Sales Tax Across US States
Calculate US sales tax for any state rate, add or remove tax from a price, and understand how sales tax differs from VAT and which goods are typically exempt.
Rule of 72: The Mental Maths Shortcut Every Investor Should Know
Use the Rule of 72 to instantly estimate how long money takes to double at any interest rate — and apply it to debt, inflation, and investment decisions.
Pythagorean Theorem Calculator: Finding the Missing Side of a Right Triangle
Use the Pythagorean theorem to find any side of a right triangle — with worked examples, the converse test, and real-world applications in construction and navigation.
Quadratic Equation Solver: The Quadratic Formula Explained
Solve any quadratic equation using the quadratic formula — understand the discriminant, real vs complex roots, and factoring as an alternative method.
Fraction to Decimal Converter: Methods, Common Values, and When Each Form Is Better
Convert fractions to decimals by division or long division, recognise recurring decimals, and know when to use fractions vs decimals in calculations.
Percentage Calculator: Solving Every Type of Percentage Problem
Master all five types of percentage problems — find a percentage, percentage of a number, reverse percentage, and percentage change — with quick mental maths tricks.
Area Calculator: Formulas for Every Shape
Calculate the area of circles, rectangles, triangles, trapezoids, parallelograms, and irregular shapes — with formulas, worked examples, and unit conversion tips.
Volume Calculator: Formulas for Spheres, Cylinders, Cones, and More
Calculate the volume of any 3D shape — sphere, cylinder, cone, cube, pyramid — with formulas, unit conversions, and practical examples.
Square Root Calculator: Methods, Properties, and Common Values
Calculate square roots, cube roots, and nth roots — understand rational vs irrational roots, simplifying surds, and practical uses in geometry and physics.
Logarithm Calculator: Understanding Log, ln, and Log Base 10
Understand logarithms — what they mean, the change of base formula, natural log vs log₁₀, and where logarithms appear in science, finance, and computing.
Trigonometry Calculator: Sin, Cos, Tan and Solving Triangles
Calculate sine, cosine, and tangent — understand the unit circle, inverse trig functions, and how to solve any triangle with the law of sines and cosines.
Factorial Calculator: What n! Means and Why It Grows So Fast
Understand factorials, how they relate to permutations and combinations, Stirling's approximation for large values, and where factorials appear in probability.
Permutation and Combination Calculator: Counting Arrangements and Selections
Calculate permutations (ordered arrangements) and combinations (unordered selections) — understand when to use each and how they apply to probability and statistics.
LCM and GCD Calculator: Lowest Common Multiple and Greatest Common Divisor
Calculate the LCM and GCD of any set of numbers — understand the prime factorisation method, the Euclidean algorithm, and their uses in fractions and scheduling.
Ratio and Proportion Calculator: Simplifying, Scaling, and Solving
Simplify ratios, solve proportions, apply scale factors, and understand direct vs inverse proportion — with worked examples in recipes, maps, and finance.
Average Calculator: Mean, Median, Mode, and Range Explained
Calculate mean, median, mode, and range — understand when each measure of central tendency is most appropriate and how outliers affect each one.
Exponent Calculator: Powers, Roots, and Scientific Notation
Calculate powers and roots, apply the laws of exponents, convert between standard and scientific notation, and understand negative and fractional exponents.
Prime Factorization Calculator: Breaking Numbers into Prime Factors
Find the prime factorization of any number, understand the Fundamental Theorem of Arithmetic, and use prime factors to find GCD, LCM, and simplify expressions.
Matrix Calculator: Addition, Multiplication, Determinants, and Inverses
Perform matrix operations — addition, scalar multiplication, matrix multiplication, determinants, and inverse matrices — with worked examples and rules for when operations are defined.
Linear Equation Solver: One Variable, Two Variables, and Systems
Solve linear equations in one and two variables — substitution, elimination, and matrix methods — with worked examples and common mistakes to avoid.
Exponential Growth Calculator: Modelling Population, Investments, and Decay
Understand exponential growth and decay — the formula, doubling time, half-life, and real applications in biology, finance, physics, and epidemiology.
Proportion Calculator: Solving for the Unknown in a Proportion
Solve proportions using cross-multiplication, apply proportional reasoning to recipes, maps, and rates, and understand direct vs inverse proportion.
Median, Mode, and Range Calculator: Measures Beyond the Mean
Calculate median, mode, and range for any dataset — understand when the median is more meaningful than the mean and how multimodal data is handled.
Decimal to Fraction Converter: Terminating, Recurring, and Mixed Numbers
Convert terminating and recurring decimals to fractions — step-by-step methods, simplification, and how to handle mixed numbers like 2.75.
Scale Ratio Calculator: Maps, Models, and Blueprint Scaling
Calculate real distances from map scales, find the scale ratio between a model and reality, and convert measurements in technical drawings and floor plans.
Simplify Fractions: Step-by-Step Reduction to Lowest Terms
Learn how to simplify fractions to their lowest terms using GCD, with worked examples for proper fractions, improper fractions, and mixed numbers.
Perimeter Calculator: Formulas for Every Shape
Find the perimeter of squares, rectangles, triangles, circles, and polygons with the right formula. Includes worked examples and common real-world applications.
Torque Calculator: Newton-Metres, Foot-Pounds, and Inch-Pounds
Convert torque between N·m, ft·lb, and in·lb, calculate torque from force and lever arm, and understand torque applications in engines, fasteners, and machinery.
Stress and Strain Calculator: PSI, MPa, and Material Limits
Calculate mechanical stress, strain, and Young's modulus. Convert between PSI, MPa, and ksi for structural engineering, materials science, and mechanical design.
Beam Deflection Calculator: Simply Supported and Cantilever Beams
Calculate maximum deflection and bending moment for simply supported and cantilever beams under point loads and uniform distributed loads using standard formulas.
Ohm's Law Calculator: Voltage, Current, Resistance, and Power
Use Ohm's Law to find voltage, current, resistance, or power in DC circuits. Includes worked examples, the power wheel, and common circuit applications.
Concrete Mix Calculator: Volume, Bags, and Mix Ratios
Calculate how much concrete you need for slabs, footings, and columns. Find the right cement:sand:gravel ratio and how many bags to buy for your project.
Fluid Flow Calculator: Flow Rate, Velocity, and Pipe Sizing
Calculate volumetric flow rate, fluid velocity in pipes, and Reynolds number for laminar vs turbulent flow using the continuity equation and pipe flow formulas.
Power Factor Calculator: Real, Reactive, and Apparent Power
Calculate power factor, real power (W), reactive power (VAR), and apparent power (VA) for AC circuits. Understand why poor power factor increases electricity costs.
Heat Transfer Calculator: Conduction, Convection, and Radiation
Calculate heat transfer rate through conduction (Fourier's Law), convection (Newton's Law of Cooling), and radiation (Stefan-Boltzmann). Includes R-value and thermal resistance.
Gear Ratio Calculator: Speed, Torque, and RPM Conversions
Calculate gear ratio, output speed, and output torque for gear trains. Understand how gear pairs multiply torque and reduce speed in transmissions and drivetrains.
Wire Gauge Calculator: AWG, Ampacity, and Voltage Drop
Select the right wire gauge for your circuit using AWG sizing charts, calculate maximum current capacity, and determine voltage drop over long cable runs.
Hydraulic Pressure Calculator: Force, Area, and Pascal's Law
Calculate hydraulic pressure, force output, and cylinder area using Pascal's Law. Includes worked examples for hydraulic cylinders, jacks, and piston systems.
Structural Load Calculator: Dead Load, Live Load, and Load Combinations
Calculate dead loads, live loads, and factored load combinations for structural design. Understand floor load limits, load path, and basic structural safety factors.
Pump Power Calculator: Head, Flow Rate, and Efficiency
Calculate the hydraulic power and shaft power required for a pump given flow rate, head pressure, and pump efficiency. Includes worked examples for water supply and HVAC systems.
Thermal Expansion Calculator: Linear, Area, and Volumetric Expansion
Calculate how much a material expands or contracts with temperature change. Covers linear thermal expansion for pipes, rails, and bridges using the thermal expansion coefficient.
Electrical Load Calculator: Panel Size, Circuit Breakers, and Service Entry
Calculate total electrical load for a home or commercial building, determine panel size, and check that your service entry can handle connected appliances.
Pipe Sizing Calculator: Diameter, Velocity, and Pressure Drop
Size pipes correctly for water, gas, and HVAC systems. Calculate required pipe diameter for a given flow rate and velocity limit, and estimate pressure drop using Hazen-Williams.
Motor Power Calculator: Horsepower, Kilowatts, and Efficiency
Convert motor power between horsepower and kilowatts, calculate motor efficiency, and determine the electrical input power required for a mechanical load.
Pressure Drop Calculator: Darcy-Weisbach and Friction Losses
Calculate pressure drop in pipes using the Darcy-Weisbach equation. Includes friction factor estimation, minor loss coefficients, and worked examples for water and gas systems.
Horsepower and Torque Calculator: RPM, HP, and kW Relationships
Calculate engine horsepower from torque and RPM, or find torque from known HP. Understand the relationship between peak torque and peak power in internal combustion and electric motors.
Transformer Calculator: Turns Ratio, Voltage, and Current
Calculate transformer turns ratio, secondary voltage, current, and power for step-up and step-down transformers. Includes efficiency losses and worked examples.
Column Buckling Calculator: Euler's Formula and Slenderness Ratio
Calculate the critical buckling load for slender columns using Euler's formula. Covers effective length factors, slenderness ratio, and design limits for steel and timber columns.
Wind Load Calculator: Design Pressure on Buildings and Structures
Calculate wind pressure and design wind loads on buildings using basic velocity pressure and exposure category methods. Includes simplified residential and commercial examples.
Efficiency Calculator: Mechanical, Thermal, and Electrical Efficiency
Calculate efficiency as a percentage for machines, engines, and electrical systems. Compare useful output to total input power and understand energy loss breakdowns.
Reynolds Number Calculator: Laminar vs Turbulent Flow
Calculate Reynolds number to determine if flow is laminar, transitional, or turbulent in pipes, ducts, and over surfaces. Covers the formula, worked examples, and critical thresholds.
Celsius to Fahrenheit: The Complete Conversion Guide
Learn the Celsius to Fahrenheit formula, get a quick reference table for common temperatures, and understand when each scale is used worldwide.
Fahrenheit to Celsius: Formula & Table
Free F to C converter: 32°F = 0°C · 98.6°F = 37°C · 212°F = 100°C. Includes the exact formula, a printable reference table, and instant converter. No maths required.
Kilograms to Pounds: Formula, Quick Table and Free Converter
Convert kilograms to pounds with the exact formula, a reference table from 1 kg to 100 kg, and common use cases for weight conversion.
Pounds to Kilograms: Formula, Reference Table and Converter
Convert pounds to kilograms with the exact formula, reference values from 1 lb to 200 lb, and when you need pounds-to-kg conversion most.
Centimetres to Inches: Formula, Quick Table and Free Converter
Convert centimetres to inches with the exact formula, a quick reference from 1 cm to 200 cm, and practical use cases for the conversion.
Inches to Centimetres: Formula, Quick Table and Free Converter
Convert inches to centimetres with the exact formula, a reference from 1 inch to 100 inches, and height conversion table for everyday use.
Metres to Feet: Formula, Reference Table and Free Converter
Convert metres to feet with the exact factor, a reference table from 1 m to 1000 m, and practical examples including altitude and room dimensions.
Feet to Metres: Formula, Reference Table and Free Converter
Convert feet to metres with the exact formula, reference values from 1 ft to 100 ft, and examples covering altitude, height, and room dimensions.
Kilometres to Miles: Formula, Quick Table and Free Converter
Convert kilometres to miles with the exact formula, a reference table for speeds and distances, and the mental shortcut used by travellers worldwide.
Miles to Kilometres: Formula, Reference Table and Free Converter
Convert miles to kilometres with the exact formula, speed limit and distance references, and the Fibonacci trick for mental calculation.
Litres to Gallons: US vs UK Gallons, Formula and Free Converter
Convert litres to gallons — covers both US and UK gallons, the formula for each, fuel efficiency conversion, and a quick reference table.
Gallons to Litres: US vs Imperial, Formula and Free Converter
Convert gallons to litres — both US and Imperial gallons covered, with formulas, a reference table, and the key differences between the two gallon types.
Grams to Ounces: Formula, Food Weight Table and Free Converter
Convert grams to ounces with the exact formula, a food weight reference table, and the difference between avoirdupois ounces and troy ounces.
Ounces to Grams: Formula, Quick Table and Free Converter
Convert ounces to grams with the exact formula, a cooking reference table, and the distinction between avoirdupois and troy ounces.
Feet to Inches: Formula, Quick Table and Free Converter
Convert feet to inches with the exact formula, a reference table, and common use cases in construction, tailoring, and height measurements.
MPH to KM/H: Formula, Speed Reference Table and Free Converter
Convert miles per hour to kilometres per hour with the exact formula, a speed limit reference table, and common use cases for international drivers.
KM/H to MPH: Formula, Speed Reference Table and Free Converter
Convert kilometres per hour to miles per hour with the exact formula, speed limit references, and a guide for drivers visiting countries that use mph.
Stone to Kilograms: Formula, Weight Table and Free Converter
Convert stone to kilograms with the exact formula, a body weight reference from 7 to 20 stone, and why the stone is still used in the UK today.
Kilograms to Stone: Formula, Weight Table and Free Converter
Convert kilograms to stone with the exact formula, a body weight reference table, and how to express results in stone and pounds combined.
Square Feet to Square Metres: Formula
1 sq ft = 0.0929 m². Free instant converter: 500 sq ft = 46.5 m², 1,000 sq ft = 92.9 m², 2,000 sq ft = 185.8 m². Room size reference table for property listings and flooring.
Celsius to Kelvin: Formula, Quick Table and Free Converter
Convert Celsius to Kelvin with the exact formula, a scientific reference table, and when Kelvin is used in physics, chemistry, and engineering.
Megabytes to Gigabytes: Formula, Storage Reference and Free Converter
Convert megabytes to gigabytes with the exact formula, a file size reference table, and the difference between MB, MiB, GB, and GiB.
Bar to PSI: Formula, Tyre Pressure Table and Free Converter
Convert bar to PSI with the exact formula, a tyre pressure reference table, and when each pressure unit is used in automotive and industrial contexts.
Joules to Calories: Formula, Food Energy Table and Free Converter
Convert joules to calories with the exact formula, a food energy reference, and the difference between calories (cal) and kilocalories (kcal) on food labels.
Millilitres to Fluid Ounces: Formula, Drink Size Table and Converter
Convert millilitres to fluid ounces with the exact formula, a drink size reference table, and the difference between US and UK fluid ounces.
JPG to PNG: How to Convert Images Without Losing Quality
Learn when and why to convert JPG to PNG, what quality differences to expect, and how to do it free online in seconds without installing software.
PNG to JPG: Compress Images the Right Way
Understand when converting PNG to JPG makes sense, how much file size you can save, and what quality tradeoffs to expect. Free online conversion guide.
PDF to Word (DOCX): Edit PDFs Without Adobe Acrobat
Learn how to convert PDF to editable Word documents for free. Understand what formatting carries over, what gets lost, and how to get the best results.
Word to PDF: Publish Documents That Look Right Everywhere
Convert DOCX to PDF to lock in your formatting, fonts, and layout. Learn when PDF is the right output format and how to convert free online.
JPG to DWG: Turn a Photo Into a CAD Drawing
Learn how JPG to DWG conversion works, what the output contains, and how architects, engineers, and designers use this conversion in their workflow.
PNG to DWG: Create AutoCAD Files From Images
A practical guide to converting PNG images to DWG CAD format. Learn the workflow, what output to expect, and how to use the result in AutoCAD.
PNG to WebP: Cut Image File Size 30% for Faster Sites
WebP delivers smaller files than PNG with equal or better visual quality. Learn how to convert PNG to WebP and why it improves your website performance.
WebP to PNG: Convert to a Universally Compatible Format
Need to use a WebP image in software that does not support it? Learn how to convert WebP to PNG quickly and when this conversion is the right choice.
PDF to Text: Extract Plain Text From Any PDF File
Learn how to extract plain text from PDFs for analysis, data processing, or editing. Understand the difference between text-based and scanned PDFs.
MP3 to WAV: When and Why to Convert to Lossless Audio
Understand the difference between MP3 and WAV, when converting makes sense, and what quality changes to expect. Free online MP3 to WAV conversion.
WAV to MP3: Compress Audio Without Losing Clarity
WAV files are large. MP3 files are portable. Learn how to convert WAV to MP3 with the right bitrate settings to preserve audio quality while reducing file size.
JPG to DXF: Convert Photos to AutoCAD Exchange Format
DXF is the universal CAD exchange format. Learn how to convert a JPG image to DXF, what the output contains, and how to use it across different CAD applications.
PNG to DXF: Raster Images to Vector CAD Files
Learn how to convert PNG images to DXF format for use in CAD applications. Ideal for logos, technical drawings, and schematics that need to be in CAD format.
STL to DWG: Convert 3D Print Files to AutoCAD Format
STL is the standard for 3D printing. DWG is the standard for CAD engineering. Learn how to bridge these two worlds and when this conversion is useful.
OBJ to DWG: Turn 3D Models Into CAD Drawings
OBJ is widely used in 3D modelling and animation. DWG is the engineering standard. Learn how and when to convert OBJ files to DWG format.
FBX to DWG: Game and Animation Models to CAD Format
FBX is the standard for game engines and animation. DWG is the standard for engineering. Learn when this conversion is needed and what to expect from the output.
STL to DXF: From 3D Print Format to 2D CAD Exchange
Learn how to convert STL files to DXF format for use across CAD applications. Understand what the output contains and how to use it in your workflow.
OBJ to DXF: Convert Wavefront Models to CAD Format
Convert OBJ 3D models to DXF for use in any CAD application. Understand what carries over, what does not, and which workflows benefit most from this conversion.
STL to OBJ: Convert Between the Two Major 3D Formats
STL and OBJ are both common 3D formats, but OBJ supports more features. Learn when converting STL to OBJ is beneficial and what you gain from the conversion.
OBJ to FBX: Prepare 3D Models for Unity and Unreal Engine
FBX is the standard for game engines and animation pipelines. Learn how to convert OBJ to FBX and what this enables in Unity, Unreal, and Maya workflows.
MOV to MP4: Convert Apple Video to Universal Format
MOV is Apple-native. MP4 is universal. Learn why converting MOV to MP4 solves playback and upload problems, and how to do it free online.
MP4 to AVI: When the Older Format Still Makes Sense
AVI is an older format, but some software and hardware still require it. Learn when converting MP4 to AVI is the right call and what quality to expect.
WebM to MP4: Convert Browser Video to Universal Format
WebM is optimised for web browsers but has limited support elsewhere. Learn how to convert WebM to MP4 for universal compatibility across devices and apps.
HTML to MP4: Record Web Animations and Pages as Video
Learn how HTML to MP4 conversion works, what it captures, and when recording a web page or animation as a video file is the right approach.
TXT to BAT: Create Windows Batch Scripts From Text Files
A BAT file is just a renamed text file with batch commands. Learn how to convert TXT to BAT, what batch scripts can do, and how to run them safely on Windows.
Video Format Conversion Guide 2026 | MP4, MOV, AVI, MKV, WebM
Master video format conversion with our 2026 guide. Learn when to use MP4, MOV, AVI, MKV, or WebM formats. Discover codec differences, quality optimization, and best practices for social media, editing, and streaming. Compare formats with detailed tables and examples.
Audio Format Conversion Guide 2026 | MP3, FLAC, WAV, AAC, M4A
Complete guide to audio format conversion in 2026. Learn when to use MP3, FLAC, WAV, AAC, M4A, OGG, and more. Understand lossy vs lossless formats, bitrate optimization, and best practices for music, podcasts, and professional audio. Detailed comparison tables and conversion recommendations.
Office Document Conversion Guide 2026 | DOCX, XLSX, PPTX, PDF, ODT
Master office document conversion with our 2026 guide. Learn how to convert Word, Excel, PowerPoint, PDF, and OpenOffice formats. Discover formatting preservation techniques, cross-platform compatibility, and collaboration best practices. Essential for professionals working across Microsoft Office, Google Workspace, and LibreOffice.
Batch File Conversion Guide 2026 | Convert 10+ Files Simultaneously
Master batch file conversion with our comprehensive guide. Learn how to convert multiple documents, images, audio, and video files at once, saving time and effort.
PDF to Word Conversion Guide 2026 | Preserve Formatting Perfectly
Learn how to convert PDF to Word (DOCX) while preserving formatting, images, and tables. Complete guide covering free tools, best practices, and troubleshooting.
Image Format Conversion Guide 2026 | JPG, PNG, WebP, HEIC
Complete guide to image format conversion. Learn when to use JPG, PNG, WebP, SVG, and other formats. Optimize images for web, print, and social media.
Currency Conversion Guide 2025 | Save Money on Forex
Master currency conversion with our comprehensive 2025 guide. Learn about exchange rates, fees, best practices, and how to save money on international transactions.
How to Save Money on International Money Transfers: 10 Expert Tips
Discover 10 proven strategies to reduce fees and get better exchange rates on international money transfers. Save up to 15% on every transaction.
Cryptocurrency Conversion Guide for Beginners | 2025
Learn how to convert cryptocurrencies safely and efficiently. Complete guide covering Bitcoin, Ethereum, exchanges, wallets, and security best practices.
GPA Conversion Guide: US, UK & European Systems | 2025
Complete guide to converting GPA between US (4.0), UK (First/Second Class), and European (ECTS) grading systems. Essential for college applications.
File Compression Guide 2025 | Reduce Size 70-95%
Master file compression with our complete 2025 guide. Learn techniques to compress PDFs, images, videos, and documents without losing quality.