A marathon is 42.195 kilometers, or 26.219 miles. The finish time is your average pace multiplied by that full distance. A fast 10K pace copied onto the marathon will not survive it, which is why the clock times below are wide.
Marathon pace chart from 2:30 to 6:00
Pace is the finish time divided by 42.195 km. Minutes per mile use 26.219 miles. The 5K column is that same pace held for 5 km. Times are rounded to the nearest second.
| Finish | min/km | min/mile | Each 5K |
|---|---|---|---|
| 2:30:00 | 3:33 | 5:43 | 17:46 |
| 2:45:00 | 3:55 | 6:18 | 19:33 |
| 3:00:00 | 4:16 | 6:52 | 21:20 |
| 3:15:00 | 4:37 | 7:26 | 23:06 |
| 3:30:00 | 4:59 | 8:01 | 24:53 |
| 3:45:00 | 5:20 | 8:35 | 26:40 |
| 4:00:00 | 5:41 | 9:09 | 28:26 |
| 4:15:00 | 6:03 | 9:44 | 30:13 |
| 4:30:00 | 6:24 | 10:18 | 32:00 |
| 4:45:00 | 6:45 | 10:52 | 33:46 |
| 5:00:00 | 7:07 | 11:27 | 35:33 |
| 5:15:00 | 7:28 | 12:01 | 37:20 |
| 5:30:00 | 7:49 | 12:35 | 39:06 |
| 5:45:00 | 8:11 | 13:10 | 40:53 |
| 6:00:00 | 8:32 | 13:44 | 42:40 |
A sub-3 marathon means every kilometer averages faster than 4:16 (6:52 per mile). A four-hour marathon is 5:41/km or 9:09/mile, and each full 5K split is 28:26 if the pace stays even. The last 2.195 km after 40 km is a short split, about 12:29 at four-hour pace, not another 28 minutes.
The marathon pace calculator builds that table from any finish time you enter. The split calculator switches the interval to miles if the course is marked that way.
Where 4:00:00 actually is on the course
At 5:41/km:
- 10K: 56:53
- Half (21.0975 km): 2:00:00
- 30K: 2:50:38
- 40K: 3:47:31
- Finish: 4:00:00
Coming through halfway in 1:55:00 feels comfortable and spends the four-hour budget. You would need the second half in 2:05:00 or faster to still finish at 4:00. Many first marathons do the opposite of what the runner intended and slow more than that.
Predicting it from a shorter race
The race time predictor scales a 5K, 10K, or half with Riegel’s formula. A 25:00 5K projects a marathon just under four hours, and that projection assumes you are trained for the distance. How long a half marathon takes is the better comparison if your longest race so far is 13.1 miles. Doubling that clock is not the same formula.
Wall-clock goals are personal. The arithmetic above only tells you the pace the goal requires. How to run a sub-4 hour marathon expands the 4:00 row. Average marathon times by age is a set of wide planning bands, not a median you have to hit.