How to Calculate Speed

Speed tells you how much ground is covered in a given amount of time. Divide the distance travelled by the time it took.

Here $v$ is the speed, $x$ is the distance and $t$ is the time. The same relationship rearranges into $x = vt$ and $t = \dfrac{x}{v}$, so knowing any two of the three fixes the third.

Example

With a distance of 120 and a time of 2, $v = 120 \div 2 = 60$. If the distance was in kilometres and the time in hours, that is 60 km/h.

Notes

The calculator assumes no units. The unit of the answer comes from the units you type in: kilometres and hours give km/h, metres and seconds give m/s. Make sure the two inputs belong together before you divide.

Enter the time as a decimal, not as hours and minutes. An hour and a half is 1.5 and an hour and a quarter is 1.25; typing 1.3 would mean 1 hour and 18 minutes.

What comes out is the average speed over the whole trip. It says nothing about how fast you were going at any single moment, which is why a car that stops at lights can still average a respectable figure. A time of 0 leaves nothing to divide by, so no speed exists.