Method and practical guide
Speed conversion for km/h, mph, m/s, and knots
Compare speed units used in road travel, running, weather, marine navigation, and aviation.
How it is calculated
Meters per second are the reference. The source is normalized to m/s and then converted to the target distance-per-time unit.
Reference values
- 1 m/s = 3.6 km/h
- 1 mph = 1.609344 km/h
- 1 knot = 1.852 km/h
- 1 ft/s = 0.3048 m/s
Worked examples
- 100 km/h is about 62.1371 mph
- 10 m/s = 36 km/h
- 20 knots = 37.04 km/h
Common uses
International speed limits, training data, wind reports, boat speeds, and flight data often use different units.
Accuracy and scope
The unit relationships are fixed, but instrument readings, average speed, instantaneous speed, and real-world conditions describe different things.