Type a value into any field and instantly see it converted across mph, km/h, knots, m/s and ft/s.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Mph, km/h, knots, m/s and ft/s all update together the moment you type.
Built on internationally defined values, not rounded approximations.
No accounts, no uploads — every calculation stays on your device.
Enter a speed in whichever unit you already have, and the rest fill in automatically.
Speed is distance divided by time, but the units used to express it vary by country and by field. Road speeds are posted in mph in the US and UK, and in km/h almost everywhere else. Aviation and marine navigation use knots, while science and engineering default to the SI unit of meters per second.
All conversions here route through meters per second as a common base, using exact definitions: a mile is exactly 1.609344 kilometers, a nautical mile is exactly 1,852 meters, and a foot is exactly 0.3048 meters. Because these are exact definitions rather than measured approximations, the results are mathematically precise.
Multiply mph by 1.609344 to get km/h. A 60 mph speed limit is exactly 96.56064 km/h.
A knot is one nautical mile per hour. It equals about 1.15078 mph or 1.852 km/h, and is standard in aviation and shipping.
Meters per second is the SI unit, so using it internally avoids compounding rounding errors between the other four units.
Wind speed is often reported in knots or m/s, while running pace tools usually work in mph or km/h — this converter bridges both.
Common questions about converting between mph, km/h, knots, m/s and ft/s.
One mile per hour equals exactly 1.609344 kilometers per hour, because a mile is internationally defined as exactly 1.609344 kilometers.
One knot (one nautical mile per hour) equals exactly 1.150779448 mph, or about 0.514444 meters per second, since a nautical mile is defined as exactly 1,852 meters.
Multiply meters per second by about 2.236936 to get mph. The exact factor is 3600 divided by 1609.344.
The constants used (1 mile = 1.609344 km, 1 nautical mile = 1852 m, 1 foot = 0.3048 m) are the exact internationally defined values, so the math is precise. Always verify figures independently for safety-critical navigation.
No. Every conversion happens locally in your browser using JavaScript. Nothing you type is sent anywhere.