A 25:00 5K is 5:00 per kilometer at age 25 and at age 55. Age changes who is likely to run that time. It does not change the division.
There is no single measured average pace for an age and a distance. Large races mix walkers, first-time finishers, and club runners, and the medians differ by event. The bands below are wide coaching ranges for people who are out to finish. Elites are faster. A first jog is often slower. A recent race of your own replaces the row.
Planning ranges
| Age | 5K | 10K | Half marathon | Marathon |
|---|---|---|---|---|
| 20–29 | 22:00–32:00 | 48:00–1:10 | 1:45–2:15 | 3:30–4:30 |
| 30–39 | 23:00–34:00 | 50:00–1:14 | 1:50–2:20 | 3:45–4:45 |
| 40–49 | 24:00–36:00 | 52:00–1:18 | 1:55–2:30 | 3:45–5:00 |
| 50–59 | 26:00–38:00 | 56:00–1:22 | 2:05–2:40 | 4:00–5:30 |
| 60+ | 28:00–42:00 | 1:00–1:30 | 2:15–3:00 | 4:30–6:00 |
These are rounded ranges, not survey results. Training history moves the clock more than a birthday does. Easy-run speed, which is a different effort, is in average running speed by age.
What the clock means in pace
| Finish | Distance | min/km | min/mile |
|---|---|---|---|
| 25:00 | 5K | 5:00 | 8:03 |
| 55:00 | 10K | 5:30 | 8:51 |
| 2:00:00 | Half marathon | 5:41 | 9:09 |
| 4:00:00 | Marathon | 5:41 | 9:09 |
The half and the marathon share 5:41/km because 21.0975 × 2 = 42.195. Holding half-marathon pace for twice the distance is the hard part, not the arithmetic.
Use the pace calculator for a time that is not in the table. Race pages lock the distance: 5K, 10K, half marathon, and marathon.
What is a good running pace separates easy effort from race effort. Half marathon times by age and marathon times by age expand the two long columns.