Distance Speed Time Calculator
Solve any of distance, speed or time from the other two using d = s × t — pick the unknown and get the answer with the working.
How it works
d = s × t · s = d ÷ t · t = d ÷ s
Distance, speed and time are locked together by one relationship, d = s × t, so knowing any two fixes the third. Rearranging it just isolates the unknown: divide distance by time for speed, or distance by speed for time. The one rule is that units must agree — miles with miles-per-hour and hours — or the answer is meaningless.
Worked example
A car drives at 60 mi/hr for 2 hours. Distance = 60 × 2 = 120 miles. Reversing it: 120 miles in 2 hours is 120 ÷ 2 = 60 mi/hr, and 120 miles at 60 mi/hr takes 120 ÷ 60 = 2 hours.
Frequently asked questions
What is the formula linking distance, speed and time?
Distance equals speed multiplied by time (d = s × t). From it, speed = distance ÷ time and time = distance ÷ speed — the same equation solved for a different letter.
The speed I get is an average — does that matter?
Yes. Dividing total distance by total time gives the average speed over the whole trip, not the speed at any instant. Real journeys speed up and slow down, so the average smooths those out.
Do the units have to match?
They must be consistent. If speed is in miles per hour, time must be in hours and distance in miles. Mixing minutes with a per-hour speed is the most common error — convert first.
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This calculator is for educational purposes. Double-check important results before acting on them.