km/h: Standard speed unit used worldwide for road traffic and sports.
mph: Used primarily in the US and UK. 1 mph β 1.609 km/h.
Knot: Standard for maritime and aviation. 1 knot = 1 nautical mile/h β 1.852 km/h.
Mach: Speed relative to the speed of sound. 1 Mach β 1,225 km/h at sea level.
m/s: The SI unit for speed. 1 m/s = 3.6 km/h.
The converter uses high-precision conversion factors with results shown to 6 decimal places, suitable for everyday and engineering use.
Yes. The speed of sound varies with temperature, which changes with altitude. This tool uses sea level standard temperature (15Β°C) at approximately 340 m/s.
Divide km/h by 1.609344. For example, 120 km/h Γ· 1.609344 β 74.56 mph. Multiply mph by 1.609344 to convert back.
The speed of light is approximately 1,079,252,848.8 km/h (299,792,458 m/s). This tool supports speed of light as a unit.
No. All calculations happen locally in your browser. No data is uploaded to any server.
A knot is one nautical mile per hour. One nautical mile equals 1.852 km (one minute of latitude). Knots are used in marine and air navigation.