Velocity calculator: speed, distance and time
Pick the unknown, enter the other two values and the answer appears at once. Useful for physics homework, trips and running plans.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter what do you want to find?, distance, time and speed.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
v = d ÷ t, d = v × t, t = d ÷ v. Conversions: 1 m/s = 3.6 km/h and 1 mph = 0.44704 m/s exactly.
Example
Inputs: What do you want to find? = Speed, Distance = 100 m, Time = 9.58 s, Speed = 10 m/s. Result: Speed: 10.4384 m/s; In km/h: 37.5783 km/h; In mph: 23.3501 mph.
Limits and caveats
- The result is the average speed over the whole distance, not the instantaneous speed.
- Speed here is a magnitude only; direction is not taken into account.
Questions about this tool
What is the difference between speed and velocity?
Speed is a magnitude only, while velocity also has a direction. For straight-line motion in one direction they have the same size.
How do I convert m/s to km/h?
Multiply by 3.6, because a kilometer is 1000 m and an hour is 3600 s. For example, 10 m/s is 36 km/h.
Is the result the average speed?
Yes. Total distance divided by total time gives the average speed, even if the speed changed along the way.