How to use
- Choose what to work out: pace, finish time or distance.
- Enter the other two values, or tap a race preset such as Marathon.
- See pace per km and per mile, speed, race times at that pace and your splits.
Pace formula
pace = time ÷ distance
time = pace × distance
distance = time ÷ pace
pace per mile = pace per km × 1.609344
A mile is exactly 1.609344 km (NIST). Speed is the reverse of pace: 60 ÷ pace in minutes gives km/h.
Example
A 4-hour marathon (42.195 km):
- Pace: 14,400 s ÷ 42.195 = 5:41 per km
- Per mile: 9:09
- Speed: 10.55 km/h (6.55 mph)
Finish times by pace
| Pace per km (per mile) | 10K | Half marathon | Marathon |
|---|---|---|---|
| 4:00 (6:26) | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 (7:15) | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 (8:03) | 50:00 | 1:45:29 | 3:30:59 |
| 5:30 (8:51) | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 (9:39) | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 (10:28) | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 (11:16) | 1:10:00 | 2:27:41 | 4:55:22 |
Race distances
- 5K: 5 km (3.11 miles)
- 10K: 10 km (6.21 miles)
- Half marathon: 21.0975 km (13.11 miles)
- Marathon: 42.195 km (26.22 miles), set by World Athletics rules
Rounding
Times are rounded to the nearest second, with halves rounded up. A marathon at exactly 5:00 per km takes 3:30:58.5, which shows as 3:30:59. The exact pace, with hundredths of a second, is under “Exact pace”.
Converting other distances? Use the length converter.