Speed, Distance and Time Calculator

Find the speed, the distance or the time from the other two, using speed = distance ÷ time — in km/h, m/s or mph.

In hours for km/h and mph, in seconds for m/s

Result

Enter values and press Calculate to see the result.

Formula

speed=distancetime\text{speed} = \frac{\text{distance}}{\text{time}}

How far you go in each unit of time.

distance=speed×time\text{distance} = \text{speed} \times \text{time}

Rearranged to find the distance.

time=distancespeed\text{time} = \frac{\text{distance}}{\text{speed}}

Rearranged to find the time.

How to use this calculator

  1. Choose what you want to find and the units you are using.
  2. Enter the other two values in those units, then press Calculate.

Worked example

150 km in 2.5 hours

speed = distance ÷ time = 150 ÷ 2.5 = 60 km/h.

In metres per second: 60 × 1000 ÷ 3600 ≈ 16.666667 m/s.

Frequently asked questions

How do I remember the formula?

Use the triangle: D on top, S and T underneath. Cover the one you want — D = S × T, S = D ÷ T, T = D ÷ S.

How do I convert km/h to m/s?

Multiply by 5/18 (that is × 1000 ÷ 3600). To go back, multiply by 18/5.