Speed Converter
Convert speed between mph, kph, m/s, knots, ft/s, and Mach number instantly.
Speed Reference Points
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Frequently Asked Questions
How many mph is 100 kph?
100 kph = 62.14 mph. To quickly estimate: kph ÷ 1.609 = mph. Or multiply mph × 1.609 to get kph.
What is Mach 1?
Mach 1 is the speed of sound — approximately 343 m/s (1,235 kph / 767 mph) at sea level at 20°C. At higher altitudes where it’s colder, the speed of sound is lower. Mach 2 = twice the speed of sound.