How average speed is found
Average speed is the total distance covered divided by the total time taken. It tells you the steady pace that would have produced the same trip, even if the real journey sped up and slowed down.
Your distance and time are first converted to meters and seconds, the speed is computed, and the result is then shown in three common units so you can compare easily.
- Meters per second for physics and scientific work.
- Kilometers per hour and miles per hour for everyday travel.
Reading the result
All three figures describe the same speed in different units, so use whichever fits your context. To roughly convert in your head, km/h is about 0.62 of mph and m/s is about 3.6 times smaller than km/h.
Practical tips
Match the units to your data rather than converting by hand first. The tool handles mixed units, such as miles with hours or meters with seconds.
- For a running pace, enter the race distance and your finishing time.
- For travel planning, enter the trip distance and expected duration.
Caveats
This is average speed, not instantaneous or top speed. A car that stops at lights will show a lower average than its cruising speed.
Time must be greater than zero, and the answer is only as accurate as the distance and time you measure.
Formula
speed = distance / timeFrequently asked questions
- How do I calculate average speed?
- Divide the total distance by the total time. The result is shown in m/s, km/h and mph so you can use whichever suits.
- What is the difference between average and instantaneous speed?
- Average speed covers the whole journey including stops. Instantaneous speed is what the speedometer reads at one moment, which is usually higher.
- How do I convert km/h to mph?
- Multiply by roughly 0.6214. The calculator shows both, so you rarely need to do it by hand.