The relationship between speed, distance, and time is one of the most useful formulas in everyday life — for travel planning, running training, physics problems, and fuel calculations. Once you know two of the three values, you can always find the third.
Enter any two values to instantly find the third.
Calculate Now →How fast something is moving
How far something travels
How long a journey takes
A helpful memory trick: arrange them in a triangle. Cover whichever variable you're solving for, and the remaining two show you the operation.
| Problem | Formula | Answer |
|---|---|---|
| Car travels 240km in 3 hours. Speed? | 240 ÷ 3 | 80 km/h |
| Plane at 850km/h for 4.5 hours. Distance? | 850 × 4.5 | 3,825 km |
| Cyclist at 25km/h covers 60km. Time? | 60 ÷ 25 | 2.4 hours (2h 24min) |
| Runner at 10km/h for 45 minutes. Distance? | 10 × (45/60) | 7.5 km |
Speed is a scalar — it only has magnitude (e.g. 60 km/h). Velocity is a vector — it has both magnitude and direction (e.g. 60 km/h north). In everyday calculations, speed is usually sufficient.
For average speed over a trip with stops, use total distance divided by total time including stops. For example: 200km in 3 hours including a 30-minute stop = 200 ÷ 3 = 66.7 km/h average speed.
Free, instant, accurate. No sign-up required.
Open Speed Calculator →