Speed
Convert speeds effortlessly between kilometres per hour, miles per hour, metres per second, knots and more. Useful for travel, sport, aviation and technical calculations.
Frequently asked questions
100 miles per hour (mph) equals 160.93 km/h. Multiply mph by 1.60934 to get the equivalent in km/h.
Kilometres per hour (km/h) expresses how many kilometres are covered per hour. Metres per second (m/s) is the SI unit for speed. The ratio is: 1 m/s = 3.6 km/h.
A knot is one nautical mile per hour, equal to 1.852 km/h or 0.5144 m/s. Knots are used in maritime and aviation contexts to express speed and wind strength.
Mach 1 is the speed of sound in air — at 20 °C at sea level, that is approximately 343 m/s or 1,235 km/h. The exact value depends on temperature and air pressure.