Speed Calculator

Calculate velocity and speed in m/s, km/h, and mph from distance and time.

Calculate For

Distance

Time

Speed

75 km/h or mph

Guide & Educational Reference

How to Use the Speed Calculator

1Set 'Calculate For' to Speed to solve v = d / t (you can also switch to Distance or Time).
2Enter the Distance travelled and the Time taken, using consistent units such as km and hours.
3Read the calculated Speed below, rounded to two decimals, in the matching unit (km/h, mph, m/s and so on).

What This Calculator Does

The Speed Calculator works out how fast something moves from the distance it covered and the time it took, using speed = distance ÷ time. It is the same three-mode motion solver as the Speed, Distance & Time Calculator, opened with Speed as the default mode, so you can also switch it to find distance or time. Typical uses are average driving or cycling speed, running pace checks and basic physics problems.

Formulas Used by THE CALC

Speed (default)

The default calculation. Needs Distance and Time.

Speed = Distance ÷ Time

Distance (same tool)

Available by switching 'Calculate For' to Distance.

Distance = Speed × Time

Time (same tool)

Available by switching 'Calculate For' to Time.

Time = Distance ÷ Speed

Practical Real-World Examples

Car covering 150 miles in 2 hours

Speed = 150 ÷ 2 = 75

→ 75.00 mph (inputs were miles and hours)

Cyclist riding 400 km over 8 hours

Speed = 400 ÷ 8 = 50

→ 50.00 km/h

100-metre sprint in 9.58 seconds

Speed = 100 ÷ 9.58 ≈ 10.44

→ 10.44 m/s

Tips & Considerations

Distance ÷ time gives average speed for the whole trip, not top speed.
Units pass straight through: km and hours give km/h, metres and seconds give m/s. The tool does not convert units.
A Time of 0 returns 'Division by zero is undefined'.
Distance must be greater than zero; negative distance or time is rejected.
Need distance or time instead? Change 'Calculate For' — this is the full Speed, Distance & Time solver.