Maths / Travel
Speed, Distance, and Time Calculator
Work out speed, distance, or time from the other two, in km/h, mph, m/s, or knots and kilometres, miles, metres, nautical miles, or feet, with the running pace too.
Speed, Distance, and Time Calculator: Speed is distance divided by time, so distance is speed multiplied by time and time is distance divided by speed. The calculator converts everything to metres and seconds first, using exact definitions (a mile is 1,609.344 m and a nautical mile 1,852 m), then converts back. A marathon of 42.195 km in 3 hours 30 minutes is an average of 12.06 km/h, or 4:59 per kilometre. Runs 100% locally in your browser with zero server file uploads.
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Write the time as h:mm:ss or mm:ss, as hours (1.5), or as 1h 30m.
Averages hide the stops
Average speed is total distance over total time, including stops. Driving 100 km at 100 km/h and then 100 km at 50 km/h averages 66.7 km/h, not 75, because more time is spent at the slower speed.
To convert a single speed between units, use km/h to mph or knots to km/h.
Common reference speeds
Walking is about 5 km/h (3 mph), easy running 9–11 km/h, cycling 15–25 km/h, and a cruising airliner around 900 km/h. Sound travels at about 343 m/s in air at 20 °C.
How to use it
- Choose what to find: speed, distance, or time.
- Enter the other two values and pick their units.
- Read the result in every unit, and the pace per kilometre and mile for speeds.
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Frequently asked questions
How do I enter the time?
As hours, minutes, and seconds separated by colons (1:30:00), as minutes and seconds (45:30), as decimal hours (1.5), or as 1h 30m.
What is pace?
The time taken for each kilometre or mile, which runners use instead of speed. It is the reciprocal of speed: 12 km/h is a pace of 5:00 per kilometre.
What is a knot?
One nautical mile per hour, 1.852 km/h, used at sea and in aviation because a nautical mile is about one minute of latitude.
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