Tools · Speed converter
Speed Converter
Six units, one tool. Edit any field and the other five update live: miles per hour, kilometers per hour, knots, meters per second, feet per second, and Mach. Built for travelers, pilots, sailors, runners, and anyone solving a physics problem.
Base unit m/s · 1 mph = 0.44704 m/s · 1 knot = 0.514444 m/s · 1 fps = 0.3048 m/s · Mach 1 = 343 m/s
The six units, briefly
MPH and KPH are the road-speed units. Miles per hour covers the US, UK, and a handful of others; kilometers per hour covers the rest of the world. Knots (nautical miles per hour) are used in aviation and at sea, because a nautical mile maps to one minute of latitude. Meters per second is the SI standard that shows up in every physics class. Feet per second appears in ballistics and US engineering. Mach is not a fixed speed at all: it is a ratio to the local speed of sound, which is why Mach 1 is slower high in the cold atmosphere than at sea level.
Common speeds in every unit
| m/s | km/h | mph | knots | fps | Mach | |
|---|---|---|---|---|---|---|
| Brisk walk | 1.50 | 5.4 | 3.4 | 2.9 | 4.9 | 0.004 |
| Easy run | 3.00 | 10.8 | 6.7 | 5.8 | 9.8 | 0.009 |
| City driving | 13.40 | 48.2 | 30.0 | 26.0 | 44.0 | 0.039 |
| Highway cruise | 28.00 | 100.8 | 62.6 | 54.4 | 91.9 | 0.082 |
| High-speed train | 83.30 | 299.9 | 186.3 | 161.9 | 273.3 | 0.243 |
| Cruising airliner | 250.00 | 900.0 | 559.2 | 486.0 | 820.2 | 0.729 |
| Speed of sound (Mach 1) | 343.00 | 1234.8 | 767.3 | 666.7 | 1125.3 | 1.000 |
Single-unit converters
- MPH to KPH and KPH to MPH — the two road-speed directions, with full tables.
- Knots to MPH and Knots to KPH — for marine and aviation gauges.
- m/s to MPH and m/s to KPH — for physics homework.
- Running pace converter — pace and speed for runners.
- Live GPS speedometer — your real speed in the browser.
FAQ
How do you convert mph to m/s?
Multiply the speed in mph by 0.44704 to get meters per second. For example, 60 mph times 0.44704 is 26.82 m/s. Going the other way, multiply m/s by 2.2369362921 to get mph.
What is Mach 1 in mph and km/h?
Mach 1 is the speed of sound, about 343 m/s at sea level and 20 degrees Celsius, which is roughly 767 mph or 1,235 km/h. The exact figure drops with altitude and temperature because the speed of sound depends on air density.
How many knots is 100 km/h?
100 km/h is about 54 knots. One knot is one nautical mile per hour, exactly 1.852 km/h, so you divide km/h by 1.852.
Which speed unit is the scientific standard?
Meters per second (m/s) is the SI base unit for speed. Road traffic uses km/h or mph, aviation and shipping use knots, and supersonic speeds are given as a Mach number.