Speed Converter
Convert MPH, KPH, Knots, Mach & more.
Common Units
High Speed Units
Quick Presets:
Primary Conversion
100 kph = 62.1 mph
Speed Comparison (Scale)
Speed Limits Reference
| Context | KPH | MPH |
|---|---|---|
| School Zone | 30 kph | ~19 mph |
| City Driving | 50 kph | ~31 mph |
| Highway | 100 kph | ~62 mph |
| Expressway | 120 kph | ~75 mph |
| Sound (Sea Level) | 1235 kph | ~767 mph |
Units of Speed Explained
MPH vs. KPH
KPH (Kilometers per Hour): The standard unit used in most of the world (Europe, Asia, Australia) for road signs and car speedometers.
MPH (Miles per Hour): Used primarily in the USA and UK. Since 1 Mile ≈ 1.6 Kilometers, 100 KPH is roughly 62 MPH.
Knots (Nautical Miles per Hour)
Used exclusively in aviation (planes) and maritime (ships). A nautical mile is based on the circumference of the Earth (1 minute of latitude).
1 Knot ≈ 1.852 KPH
Mach Number
Used for high-speed aircraft and missiles. It is the ratio of the speed of the object to the speed of sound.
Mach 1 = Speed of Sound (approx 1235 km/h at sea level).
Anything above Mach 1 is "Supersonic".
Conversion Formulas
1 MPH = 1.60934 KPH1 m/s = 3.6 KPH1 Knot = 1.852 KPH1 Mach ≈ 1234.8 KPH