Speed Converter
Convert between 6 speed units — m/s, km/h, mph, knots, ft/s, Mach.
Frequently asked questions
What is a knot?
A knot is exactly 1 nautical mile per hour, or approximately 1.852 km/h (1.151 mph). It is the standard unit of speed in maritime and air navigation because one knot equals one arcminute of latitude per hour, making chart calculations straightforward.
What is Mach 1?
Mach 1 is the speed of sound at sea level in dry air at 20°C — approximately 343 m/s (1,235 km/h / 767 mph). The speed of sound varies with temperature and altitude; at cruising altitude (~10,000 m) it drops to about 295 m/s. This converter uses the sea-level value.
How many km/h is 100 mph?
100 mph = 160.934 km/h. The conversion factor is 1.60934 (the number of kilometres in a statute mile). A quick mental shortcut: multiply mph by 1.6 for an approximate km/h value.
