Health & Fitness 2026-05-03 5 min read By Konvertibly Team

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.

Heart Rate Training Zones: The Complete Guide

Training at the right intensity is the key difference between effective workouts and wasted effort. Heart rate zones allow you to precisely target different physiological systems — fat burning, aerobic base, lactate threshold, or maximum output.

Estimating Maximum Heart Rate

Traditional: Max HR = 220 − age
Tanaka formula: Max HR = 208 − (0.7 × age)  ← more accurate over 40

The 5 Training Zones

Zone 1 (50–60% Max HR): Active recovery. Very easy, conversational pace.
Zone 2 (60–70% Max HR): Fat-burning / aerobic base. Sustainable for long periods.
Zone 3 (70–80% Max HR): Aerobic / cardio. Improves cardiovascular efficiency.
Zone 4 (80–90% Max HR): Lactate threshold. Hard effort, sustainable for 20–40 min.
Zone 5 (90–100% Max HR): VO₂ max / sprint. Maximum effort, short bursts only.

Example: 35-year-old (Max HR ≈ 185 bpm)

Zone 1: 93–111 bpm
Zone 2: 111–130 bpm
Zone 3: 130–148 bpm
Zone 4: 148–167 bpm
Zone 5: 167–185 bpm

Which Zone Should You Train In?

For general health and fat loss, spend 80% of training time in Zone 2 and 20% in Zone 4. This "polarised" approach is used by elite endurance athletes and supported by a growing body of research.

Calculate your heart rate zones: Free Heart Rate Zones Calculator