Speed, Distance and Time Calculator
Enter any two of speed, distance and time and this calculator finds the third using speed = distance / time. Choose units for each value independently.
How to calculate speed, distance or time
- Choose whether to solve for speed, distance or time.
- Pick the units for each value.
- Enter the two known values and read the result.
Examples
Average speed
distance = 100 km, time = 2 h
speed = 50 km/h
Distance travelled
speed = 50 km/h, time = 2 h
distance = 100 km
Frequently asked questions
What is the speed distance time formula?
Speed equals distance divided by time (s = d / t). Rearranged, distance = speed x time and time = distance / speed.
Can I mix units like km and mph?
Yes. Each value has its own unit and the calculator converts through SI internally, so km distance with an mph speed works fine.
How do I convert km/h to m/s?
Divide by 3.6. For example 36 km/h is 10 m/s. Select m/s as the speed unit and the calculator does this for you.
Does this give average or instantaneous speed?
It gives average speed over the whole trip: total distance divided by total time. It does not account for changes in pace.
Why must time and speed be above zero?
Dividing by zero time or zero speed is undefined, so those inputs are rejected when they would be the divisor.
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