This calculator solves any one of speed, distance, or time when you know the other two — the classic relationship behind every journey estimate, physics homework problem, or pace check. Choose what to solve for, enter the two known values, and the answer appears instantly.
How it works
The three quantities are linked by one rule, rearranged depending on what you need:
- Speed = distance ÷ time
- Distance = speed × time
- Time = distance ÷ speed
Speed is treated as a per-hour figure (km/h or mph), so distance must be in the matching unit (km or miles) and time in hours. When you solve for time, the decimal-hours result is also broken down into whole hours and minutes for readability.
Example
Solving for time with a speed of 90 km/h over a distance of 450 km:
- Time = 450 ÷ 90 = 5 hours (shown as 5h)
Solving for speed instead, with 450 km covered in 5 hours: 450 ÷ 5 = 90 km/h.
| Solve for | Inputs | Result |
|---|---|---|
| Time | 90 km/h, 450 km | 5h |
| Speed | 450 km, 5 h | 90 |
| Distance | 90 km/h, 5 h | 450 |
Use any consistent unit pair (km with km/h, or miles with mph). It all runs in your browser, so nothing is uploaded.