Does this calculator work in miles per hour?

The calculator uses kilometers and hours. Convert distance to kilometers first, or convert the resulting speed from km/h to mph by dividing by 1.60934.

Does this give average speed or instantaneous speed?

It calculates average speed over the full distance and time entered, not instantaneous speed at any single moment.

Speed Calculator

Calculate speed, distance or time from the other two values

Distance

Time

hrs

Values are in kilometers and hours. Need miles or another unit? Convert with the Unit Converter first.

What is the Speed Calculator?

The Speed Calculator solves the classic speed–distance–time relationship: given any two of the three values, it calculates the third. It's useful for trip planning, physics homework, or working out average pace.

How to Use the Speed Calculator

Choose what to calculate — Speed, Distance or Time.
Enter the two known values in the remaining fields.
Read the result — it updates instantly as you type.

The Speed Formula

Speed = Distance ÷ Time
Distance = Speed × Time
Time = Distance ÷ Speed

Example

If you drive 150 km in 2 hours, your average speed is 150 ÷ 2 = 75 km/h. Conversely, at 75 km/h for 3 hours, you'd cover 225 km.

Frequently Asked Questions

The calculator itself uses kilometers and hours. To work in miles, convert your distance to kilometers first using the Unit Converter, or convert the resulting speed from km/h to mph afterward (divide by 1.60934).

It calculates average speed over the full distance and time entered — it doesn't account for variations in speed during the journey (e.g. traffic stops).