Convert m/s, km/h, mph, knots, Mach, ft/s — road, sea, air and engineering.
Updated
| Unit | Value | Copy |
|---|---|---|
Millimetre per second mm/s | 16,666.66666667 | |
Centimetre per second cm/s | 1,666.66666667 | |
Metre per second m/s | 16.66666667 | |
Kilometre per hour km/h | 60 | |
Mile per hour mph | 37.28227153 | |
Knot (nautical mile / hour) kn | 32.39740821 | |
Foot per second ft/s | 54.68066492 | |
Mach (sea level, 15°C) Mach | 0.04897783 |
Quick start
Type a speed, pick the unit, read it in every other unit at once.
Enter the speed and pick its unit. Switching units converts the displayed value so the meaning is preserved.
Eight units — mm/s through Mach — update live. The source unit is highlighted.
Click Copy on any row to grab the converted value. Everything runs locally — no upload.
In-depth guide
Convert between eight speed units — including everyday km/h and mph, maritime knots, aviation Mach and engineering ft/s. Type a value, pick the source unit, every other unit updates live.
| Unit | Symbol | In m/s |
|---|---|---|
| Millimetre per second | mm/s | 0.001 |
| Centimetre per second | cm/s | 0.01 |
| Metre per second | m/s | 1 |
| Kilometre per hour | km/h | 0.277 8 |
| Mile per hour | mph | 0.447 04 |
| Knot (nm / h) | kn | 0.514 4 |
| Foot per second | ft/s | 0.304 8 |
| Mach (sea-level, 15 °C) | Mach | 340.29 |
When to reach for it. Use it to switch between km/h, mph, m/s and knots for travel, sport and physics problems.
When something else is better. Navigation and aviation should use the instrument and unit their procedures mandate.
The pitfall to watch. Knots (nautical miles per hour) are not the same as mph — mixing them is a classic travel-planning slip.
Everything runs on your device. The values you enter are processed locally in this browser tab — EpitomeTool does not send your input to a server, store it, or log it. That means you can use the tool offline once the page has loaded, and refreshing the tab wipes the slate.
1 knot = 1 nautical mile per hour = 1852 m / 3600 s ≈ 0.5144 m/s. The nautical mile (1852 m exactly since 1929) is one minute of latitude along any meridian, which is why knots are used in maritime and aviation navigation.
Mach 1 ≈ 340.29 m/s, the speed of sound in dry air at sea level and 15 °C (288.15 K). The actual local speed of sound depends on temperature: it's about 295 m/s at the cruise altitude of a commercial airliner (−50 °C). For precise aerodynamics, model the local atmosphere.
3600 seconds in an hour, 1000 metres in a kilometre. 3600 / 1000 = 3.6. So 10 m/s = 36 km/h, and a 100 km/h car is doing about 27.78 m/s.
1 km = 0.6214 mi exactly (1/1.609344). So 100 km/h ≈ 62.14 mph and 60 mph ≈ 96.56 km/h.
It's so much larger than every other unit (3×10⁸ m/s) that listing it forces the other rows into scientific notation for any reasonable input. If you need it, multiply m/s by 3.336 × 10⁻⁹.
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