A half marathon is 21.0975 kilometers, or 13.109 miles. Finish time divided by that distance is the pace. Age group results from one race are not a personal target, because the field and the course change the median.
The ranges below are coaching bands for recreational finishers. They are not medians from a race series. Someone racing for the first time can sit at the slower end. A runner with years of training can sit faster than the band.
Planning ranges
| Age | Finish range | Faster end | Slower end |
|---|---|---|---|
| 20–29 | 1:45–2:15 | 4:59/km (8:01/mi) | 6:24/km (10:18/mi) |
| 30–39 | 1:50–2:20 | 5:13/km (8:23/mi) | 6:38/km (10:41/mi) |
| 40–49 | 1:55–2:30 | 5:27/km (8:46/mi) | 7:07/km (11:27/mi) |
| 50–59 | 2:05–2:40 | 5:55/km (9:32/mi) | 7:35/km (12:12/mi) |
| 60+ | 2:15–3:00 | 6:24/km (10:18/mi) | 8:32/km (13:44/mi) |
A 2:00:00 half is 5:41/km or 9:09/mile at any age. That row is the useful comparison. The age band only says whether 2:00 is toward the faster or slower side of a wide window.
Even checkpoints for 2:00:00
At 5:41 per kilometer:
- 5K: 28:26
- 10K: 56:53
- 15K: 1:25:19
- 20K: 1:53:45
- Finish (21.0975 km): 2:00:00
The half marathon pace calculator rebuilds this from any finish time. The split calculator switches the markers to miles.
A shorter race is a better anchor
If you have a recent 10K, the race time predictor scales it with a small slowdown. Doubling a 10K clock ignores that slowdown and is usually a little fast. How long a half marathon takes is the pace chart without the age rows. Marathon times by age is the longer race, and doubling a half is not that plan.