Speed Converter
Convert speed between miles per hour, kilometres per hour, metres per second and knots.
Speed in its many units
Speed is quoted in miles per hour, kilometres per hour, metres per second in science, and knots at sea and in the air, so converting between them comes up in travel, sport, science and more. This translates a speed between the common units, so a figure from any of those worlds becomes meaningful in the one you use.
Enter a speed and see it converted.
Why knots and metres per second exist
Two of these units have specific reasons behind them. The knot, one nautical mile per hour, survives in shipping and aviation because the nautical mile is tied to the geometry of the globe, which makes navigation calculations cleaner. Metres per second is the scientific standard because it fits neatly with the rest of the metric system in physics equations. For everyday travel it is miles and kilometres per hour that matter, and converting between those two is the most common need when crossing between countries that use different ones.
Common questions
What is a knot?
One nautical mile per hour, used at sea and in aviation because the nautical mile ties neatly to the geometry of the globe for navigation.
Why does science use metres per second?
Because it fits cleanly with the rest of the metric system in physics equations, making calculations consistent.
Is anything uploaded?
No. The conversion happens in your browser.