Speed Converter
Convert speeds between metric, imperial, and nautical units.
Calculator
Use the Speed Converter
Result
—
Formula
value × (from factor ÷ to factor)
Step-by-step
- 1
Enter the speed
The speed you want to convert.
- 2
Pick the units
Choose the source and target units.
Worked example
Example input: value: 100, from: km/h, to: mph
Result: 62.1371
Related tools
- Length Converter
Convert distances.
Frequently asked questions
What is 100 km/h in mph?
About 62.14 mph. The calculator chains the fixed factors km/h to m/s or mph exactly, so highway speeds, treadmill paces, and wind speeds all convert on the same exact ladder.
How do knots relate to the other units?
One knot is 0.514444 m/s or exactly 1.852 km/h — the nautical mile per hour. Boats and aviation still report speed in knots, so the unit sits in this same dropdown next to the road units.
Why is the factor between km/h and m/s 3.6?
One hour is 3600 seconds and one km is 1000 m, so dividing one by the other leaves the clean constant 3.6: multiply km/h by dividing by 3.6 to get m/s, and reverse for the other direction.