Quick answer: Pace is time divided by distance. Running 10 km in 50 minutes is a pace of 5:00 per kilometer (8:03 per mile), a speed of 12 km/h. At that pace a half marathon takes 1:45:29 and a marathon 3:30:59, though most runners slow down over longer distances.
Pace is how long you take to cover one kilometer or mile, and it is the language runners use to plan training and races. Yet race results usually show finish times, and treadmills show speeds. This calculator converts between all of them.
Choose what to solve for. Enter a distance and a time to find your pace. Enter a distance and a target pace to see your finish time. Or enter a time and a pace to see how far you would run. The table shows what that pace would give over the standard race distances.
The arithmetic
Time = pace × distance
Distance = time ÷ pace
Speed (km/h) = 3600 ÷ pace in seconds per km
1 mile = 1.609344 km
The predictions assume you hold the same pace for the whole distance. In practice, pace slows over longer races, so a 10K pace is normally faster than the pace you can hold for a marathon. Use the table to see what a pace means in race terms, then adjust for your training and the course.
Common race distances are 5 km, 10 km, the half marathon at 21.0975 km (13.1 miles), and the marathon at 42.195 km (26.2 miles).
A worked example
Example. Running 10 km in 50:00 is a pace of 5:00 per kilometer, or 8:03 per mile, a speed of 12 km/h. At that pace a half marathon takes 1:45:29 and a marathon takes 3:30:59.
Finish times at common paces
| Pace | 5K | 10K | Half marathon | Marathon |
|---|---|---|---|---|
| 4:00 per km | 20:00 | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 per km | 22:30 | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 per km | 25:00 | 50:00 | 1:45:29 | 3:30:59 |
| 5:30 per km | 27:30 | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 per km | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 per km | 32:30 | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 per km | 35:00 | 1:10:00 | 2:27:41 | 4:55:22 |
Finish times if the same pace is held for the whole distance. The half marathon is 21.0975 km and the marathon 42.195 km.
Common mistakes to avoid
- Predicting a marathon from a 5K at the same pace. Pace drops with distance, so a marathon is usually run noticeably slower than 5K pace.
- Starting too fast. Going out faster than your target pace costs far more time later than it saves at the start.
- Mixing kilometers and miles. One mile is 1.609 km, so a 5:00 per km pace is 8:03 per mile.
Frequently asked questions
How do I calculate running pace?
Divide the time by the distance. Running 10 km in 50 minutes is 50 ÷ 10 = 5 minutes per kilometer. To get the pace per mile, multiply the pace per kilometer by 1.609.
What is a good running pace?
It depends on your age, fitness and goals. Many recreational runners run between 5:30 and 7:30 per kilometer (9:00 to 12:00 per mile). The best pace is one you can sustain and enjoy.
How do I convert min per km to min per mile?
Multiply by 1.609344. So 5:00 per kilometer is 8:03 per mile. The results table shows both.
Can I predict my marathon time from a 10K?
Roughly. Marathon pace is usually 15 to 25 seconds per kilometer slower than 10K pace for well-trained runners, and more for newer runners. The table here shows the times at a constant pace, which is a best case.
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Sources and further reading
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