How to use the speed converter
Enter a value and select its unit. The converter instantly shows the equivalent speed in every other unit — kilometres per hour, miles per hour, metres per second, feet per second, and knots — so you can read across systems at a glance. Everything runs in your browser.
One tool for road, track, air, and sea
Different fields measure speed differently: cars use km/h or mph, physics uses metres per second, and ships and aircraft use knots. Converting between them is a frequent need whether you are driving in another country, reading a weather report, or working through a physics problem. Showing all units together removes the friction of picking a single conversion direction.
Exact and instant
The conversions here use exact international definitions — a mile is exactly 1,609.344 metres, a knot exactly 1,852 metres per hour — so every result is precise, with rounding only in the display. For very large or very small values the converter switches to scientific notation to keep the answer readable. Nothing you enter is stored, and the whole calculation happens on your device.