Target pace for marathon, half and 10K
Choosing your target pace is the decision that most affects your marathon. Here is the exact pace each goal demands and the equivalent times at shorter distances.
The table starts from a marathon goal and works out the exact pace per kilometre it demands, plus the equivalent times at 5K, 10K and half marathon. Equivalents use the Riegel formula (T2 = T1 × (D2 / D1)^1.06), the same one behind the race time calculator.
| Marathon goal | Pace (min/km) | 5K | 10K | Half marathon |
|---|---|---|---|---|
| 2 h 30 min | 3:33 | 15:38 | 32:36 | 1:11:57 |
| 2 h 45 min | 3:55 | 17:12 | 35:52 | 1:19:08 |
| 3 h | 4:16 | 18:46 | 39:08 | 1:26:20 |
| 3 h 15 min | 4:37 | 20:20 | 42:23 | 1:33:32 |
| 3 h 30 min | 4:59 | 21:54 | 45:39 | 1:40:43 |
| 3 h 45 min | 5:20 | 23:28 | 48:55 | 1:47:55 |
| 4 h | 5:41 | 25:01 | 52:10 | 1:55:07 |
| 4 h 15 min | 6:03 | 26:35 | 55:26 | 2:02:18 |
| 4 h 30 min | 6:24 | 28:09 | 58:42 | 2:09:30 |
| 5 h | 7:07 | 31:17 | 1:05:13 | 2:23:53 |
The practical reading: if your best 10K is well below the equivalent your marathon goal demands, the goal is ambitious. Riegel tends to overestimate over long distances, especially in the marathon, where glycogen depletion weighs more than over 10K. A common rule is to add 2 % to 5 % to the equivalent time for marathon distances.
Choosing the pace: start slower, finish faster
The most expensive mistake in a marathon is going out faster than target in the first kilometres. You pay for it at kilometre 30, and there is no way to get it back. Two approaches that work:
- Even pace. The most efficient: divide the goal by 42.195 km and do not move. Mentally hard, physically optimal.
- Gentle negative split. Go out 5 to 10 seconds per kilometre slower than your target average and make it up in the second half. If the goal is 4:15 min/km, start at 4:22 and close at 4:08.
Heart rate rules the first half
In the first 20 km, pace should be a consequence, not an order. If your heart rate is above what you expected for that pace, the day is not built for that pace: heat, wind and hills change the cost. Afterpacer computes grade adjusted pace (GAP), which tells you what flat pace equals what you are doing uphill, so you do not confuse going slow with being tired.
To see how a marathon looks with GAP, zones and splits, open the demo with a real activity.
Frequently asked questions
What pace do I need for a 4 hour marathon?
A marathon is 42.195 km, so 4 hours means 240 minutes divided by 42.195 = 5:41 min/km. For 3 hours 30 minutes it is 4:59 min/km, and for 3 hours it is 4:16 min/km.
Is the Riegel prediction reliable for the marathon?
It is reasonable as a starting point, but it tends to be optimistic over long distances. Add 2 % to 5 % to the equivalent time for the marathon, more if it is your first or if the course has elevation.
Even pace or starting slower?
Even pace is the most efficient all else being equal. If you tend to fade, a gentle negative split (start slightly slower and make it up in the second half) protects the final hour better.