Three calculations in one: find your pace per kilometre or mile from a distance and time, predict a finish time from a distance and target pace, or work out distance from a time and pace. It is built for race planning, training, and tracking goal splits.
How it works
The tool uses the relationship between pace, time, and distance, parsing times in mm:ss or hh:mm:ss:
- Pace = total time ÷ distance (minutes per km or mile), and average speed = distance ÷ time.
- Finish time = pace × distance.
- Distance = total time ÷ pace.
Pick the mode and enter the two known values; the tool computes the third. Pace mode additionally reports your average speed in km/h and mph.
Example
You run 10 km in 50:00:
- Pace = 50:00 ÷ 10 = 5:00 per km
- Average speed = 60 ÷ 5 = 12 km/h (≈ 7.46 mph)
Predict a half marathon at that pace: 5:00 × 21.0975 km ≈ 1:45:29.
| Race | At 5:00/km |
|---|---|
| 5K | 25:00 |
| 10K | 50:00 |
| Half marathon | ~1:45:29 |
| Marathon | ~3:30:59 |
All calculations run entirely in your browser; nothing is uploaded.