Unit Conversion 2026-05-02 4 min read By Konvertibly Team

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.

Kilometres to Miles: The Complete Guide

Kilometres (km) and miles (mi) are the standard units for road distances and speed limits — but in different countries. The US, UK (roads), and a few other places use miles; the rest of the world uses kilometres. This conversion is essential for driving abroad, reading maps, and understanding international sports times.

The Conversion Formula

miles = kilometres × 0.621371

For mental arithmetic: multiply by 0.6, or use the golden ratio approximation — the Fibonacci sequence gives near-perfect results (5/8 = 0.625, very close to 0.621).

Quick Reference Table

1 km = 0.621 mi
5 km = 3.107 mi
10 km = 6.214 mi
42.195 km = 26.22 mi (marathon distance)
100 km = 62.14 mi
500 km = 310.7 mi

Speed Limits Reference

50 km/h = 31.1 mph (urban)
80 km/h = 49.7 mph (rural)
100 km/h = 62.1 mph (motorway)
120 km/h = 74.6 mph (autobahn/highway)

The Fibonacci Trick

Consecutive Fibonacci numbers (1, 1, 2, 3, 5, 8, 13, 21…) approximate km/mile pairs: 5 km ≈ 3 miles, 8 km ≈ 5 miles, 13 km ≈ 8 miles. The ratio converges to the golden ratio (~1.618), very close to 1/0.621 = 1.609.

Convert any distance instantly: Free km to miles converter