How to use the speed, distance & time calculator
The formulas
Distance = speed × time
Speed = distance ÷ time
Time = distance ÷ speed
Pick what you want to work out at the top, enter the two values you know, and the third is calculated. Units can be mixed freely — for example, speed in km/h with distance in miles — because everything is converted to a common base before the maths.
Average speed
Figures from this triangle are averages. A vehicle that covers 60 miles in 90 minutes averaged 40 mph overall, whatever its speed was at any single moment. That distinction matters whenever the numbers are used to describe a real journey.
Example
60 minutes at 30 mph = 30 miles. And the reverse: 30 miles covered in 60 minutes means an average speed of exactly 30 mph.
Frequently asked questions
What is the formula linking speed, distance, and time?
Distance = speed × time. Rearranged: speed = distance ÷ time, and time = distance ÷ speed. The three values must use matching units, which this calculator handles for you.
How far do you travel in 60 minutes at 30 mph?
30 miles. At a steady 30 miles per hour for exactly one hour, you cover 30 miles (about 48.3 km).
Does this give an exact journey time?
It gives the moving time at a perfectly steady average speed. Real journeys include slowing down, junctions, and stops, so allow extra time on top.
Can I work in km/h and kilometres?
Yes. Choose km/h for speed and kilometres for distance and the calculator converts everything consistently, showing both unit systems in the result.
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