Speed Converter
Convert between various units of speed (e.g., km/h, mph, m/s).
Enter values and units to convert speed.
What This Converter Does
A car's speedometer, a weather report's wind speed, and a ship's logbook all quote speed in different units, and none of the conversion factors between them are round numbers you'd want to calculate by hand every time. This tool takes a speed value in one unit and converts it into another instantly.
How to Use It
Enter a Value, pick a From Unit and To Unit, and click Convert. The five supported units are meters per second, kilometers per hour, miles per hour, feet per second, and knots — the field defaults to converting km/h to mph, a common one, but any pair from that list of five works the same way.
The Formula
Meters per second is the common base unit. Kilometers per hour converts by dividing by 3.6, miles per hour by multiplying by 0.44704, feet per second by multiplying by 0.3048, and knots by multiplying by 0.514444 (a knot is one nautical mile per hour). Converting between any two units passes your input through meters per second first, then divides by the target unit's own factor, rounded to 5 decimal places.
A Worked Example
100 km/h converts to 62.13712 mph: first 100 ÷ 3.6 converts to 27.77778 meters per second, then dividing that by mph's own factor of 0.44704 gives the final 62.13712. Going the other direction, 60 mph converts to 96.56064 km/h — 60 × 0.44704 = 26.8224 meters per second, then × 3.6 to reach km/h. And for a nautical example, 10 meters per second converts to 19.43846 knots, dividing by the knot's factor of 0.514444.
How to Convert Speed Manually
Route through meters per second. To convert km/h to m/s, divide by 3.6 (100 ÷ 3.6 = 27.77778); to go from m/s back to km/h, multiply by 3.6 instead. For mph, multiply by 0.44704 to reach m/s, or divide by 0.44704 to go from m/s to mph. Converting between two non-base units directly — mph to km/h, say — is easiest done as two hops through m/s rather than hunting for a single combined factor: convert your starting unit to m/s, then convert that m/s figure into your actual target unit.
FAQ
- How many kilometers per hour in a mile per hour?
- 1 mph equals approximately 1.60934 kph. Enter your value to convert between any speed units.
- What speed units are supported?
- Meters per second, kilometers per hour, miles per hour, feet per second, and knots.