Metric, imperial, and nautical speed units
Kilometers per hour and meters per second are metric, miles per hour and feet per second belong to the imperial/US system, and knots (one nautical mile per hour) come from maritime and aviation use. One mile per hour is defined as exactly 0.44704 meters per second, and one knot as exactly 1.852 km/h.
Speed conversions are exact and rest on fixed factors — for more unit pairs, use our speed conversion hub.