Speed Converter
Convert between common speed units including m/s, km/h, mph, knots, and ft/s.
Overview
Speed conversion between kilometres per hour, miles per hour, metres per second and knots is arithmetic on exact factors: 1 km/h is 0.27778 m/s, 1 mph is 1.609344 km/h, and a knot is exactly 1.852 km/h. The knot is one nautical mile per hour, and the nautical mile was defined as one minute of latitude along a meridian before being fixed at 1,852 metres.
Quick presets
結果
All Conversions
| 単位 | 値 |
|---|---|
Click a row to set it as the target unit.
Common Reference Speeds
| 説明 | km/h | mph | m/s |
|---|---|---|---|
| Walking | 5 | 3.1 | 1.39 |
| Cycling | 25 | 15.5 | 6.94 |
| Highway | 120 | 74.6 | 33.33 |
| Speed of Sound | 1,234 | 766.6 | 342.78 |
Click a row to load that speed.
Conversion Factors (base: m/s)
- 1 km/h = 1/3.6 m/s
- 1 mph = 0.44704 m/s
- 1 knot = 0.514444 m/s
- 1 ft/s = 0.3048 m/s
How to Use
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1
Enter the value
Type the amount you want to convert into the Speed Converter.
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2
Choose the units
Select the unit to convert from and the unit to convert to.
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3
Read the converted value
The conversion updates instantly in your browser — no button, nothing sent to a server.
About
That origin is why marine and aviation navigation retain the unit: a speed in knots translates directly into minutes of latitude covered per hour, which makes dead reckoning on a chart a matter of reading the latitude scale rather than converting.
Mach number is not a fixed speed but a ratio to the local speed of sound, which depends almost entirely on air temperature. Mach 1 is about 1,225 km/h at sea level in standard conditions and roughly 1,062 km/h in the cold air of the stratosphere, so an aircraft can accelerate through Mach 1 while flying no faster.