Speed Converter
Convert km/h, mph, and m/s — for driving, sport, and physics.
Convert speeds between kilometers per hour, miles per hour, and meters per second. Useful for driving abroad, running pace, cycling, and physics problems — with exact conversion factors.
How it's calculated
Every unit converts through meters per second with its exact factor: 1 km/h = 1/3.6 m/s, 1 mph = 0.44704 m/s. The result is value × factor[from] ÷ factor[to].
Frequently asked questions
How fast is 100 km/h in mph?
About 62.14 mph. Enter 100, choose km/h → mph — the exact factor is 1 km/h = 0.621371 mph.
How do I convert m/s to km/h?
Multiply by 3.6 — or use this tool. 10 m/s is exactly 36 km/h.
What about knots?
A knot is one nautical mile per hour (1.852 km/h). This converter covers km/h, mph, and m/s — the units used on roads and in most sports.