Why sailors and pilots use a different unit
The knot looks like an arbitrary holdover, but it is the one speed unit tied to the shape of the planet. A nautical mile is one minute of latitude — one sixtieth of a degree — which means a vessel travelling at one knot covers exactly one minute of latitude per hour.
For anyone navigating by chart, that removes a conversion step entirely: distance on the map and speed through the water share the same underlying unit. It is why the knot survived metrication in both marine and aviation use while almost everything else changed.
In everyday terms, one knot is 1.852 km/h or about 1.15 mph — so a ship making 20 knots is moving at roughly 37 km/h.
Everyday conversions
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.