Convert speed between mph, km/h, knots, m/s, and Mach. Type a value once and see all units at once.
Type a speed in any unit and instantly see the equivalent in mph, km/h, knots, m/s, and Mach — all at once. The source unit is highlighted so you always know your reference point. No need to convert one unit at a time.
Enter a value in the number box, then select the unit you're converting from in the dropdown. All other units update instantly in the cards below.
Mach is the ratio of an object's speed to the speed of sound. Mach 1 is approximately 343 m/s (1,235 km/h or 767 mph) at sea level at 20°C.
Knots (nautical miles per hour) are used in maritime and aviation navigation. One knot equals approximately 1.852 km/h or 1.151 mph.
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