Speed Calculator
Calculate speed, distance, or time — fill in any two values.
Select which value to calculate, then enter the other two.
Solve for speed, distance, or time
This calculator works from the fundamental relationship between speed, distance, and time: speed equals distance divided by time. Because the three quantities are linked, knowing any two lets you find the third. The tool lets you choose which value to calculate and then enter the other two, so it doubles as a speed calculator, a travel-time estimator, and a distance calculator all at once.
It is useful for runners and cyclists working out pace, drivers estimating journey times, students solving physics motion problems, and anyone planning a trip who wants to know how long a route will take at a given speed.
How to use it
Use the Set to calculate button on the row you want to solve for, which highlights that field and turns it read-only. Then type values into the other two rows. The answer fills in automatically as soon as both inputs are valid, with no separate calculate button to press.
Each row has its own unit selector. Distance supports kilometres, miles, metres, feet and nautical miles; time supports hours, minutes and seconds; and speed supports km/h, mph, m/s and knots. You can mix units freely, for example entering a distance in miles and a time in minutes to get a speed in km/h, because the tool converts everything internally before calculating.
Tips and worked example
Suppose you ran 5 kilometres in 25 minutes. Set Speed to calculate, enter 5 km for distance and 25 minutes for time, and the calculator returns your average speed of 12 km/h. Switch the speed unit to m/s and it instantly re-expresses the same result in a different unit.
Bear in mind the result is an average speed over the whole distance, not your instantaneous speed at any single moment. Results are shown to four decimal places. All conversions and calculations run entirely in your browser, so nothing you enter is sent to a server.