Marathon Pace Calculator
Enter your target marathon finish time to get the even pace, a 5 km split table and the half-by-half pace if you plan to run the second half faster. It answers questions like what pace you need for a 4 hour marathon.
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Formula
- Pace per km:
goal time in seconds / 42.195 - Pace per mile:
pace per km x 1.609344 - Split at distance d:
pace per km x d - Negative split:
first half = (T + d) / 2,second half = (T - d) / 2, whereTis the goal time anddis how much faster the second half is. Each half covers 21.0975 km.
Worked example
Goal 4:00:00 = 14,400 s.
- Even pace: 14,400 / 42.195 = 341.3 s, which is 5:41 per km and 9:09 per mile.
- 5 km split: 341.3 x 5 = 1,706 s = 0:28:26; 10 km = 0:56:53; 40 km = 3:47:31.
- With a 120 s negative split: first half 7,260 s = 2:01:00 (5:44 per km), second half 7,140 s = 1:59:00 (5:38 per km).
When to use it
Use it when you already have a goal finish time for 42.195 km and want the pace to hold on race day, plus the clock time at each 5 km mark for a pace band. For other distances or custom checkpoints, use the split time calculator.
Marathon pace by finish time
| Goal | Per km | Per mile |
|---|---|---|
| 3:00:00 | 4:16 | 6:52 |
| 3:30:00 | 4:59 | 8:01 |
| 4:00:00 | 5:41 | 9:09 |
| 5:00:00 | 7:07 | 11:27 |
Common mistakes
- Using 42 km instead of 42.195 km. Over a full marathon this is a minute or more.
- Planning on perfect pace. Allow a few seconds per km for aid stations and the watch reading long on a winding course.
- Setting a goal that is faster than your recent racing supports; check it with the race time predictor.
How it differs from nearby tools
This page converts a goal time into pace. The negative split calculator plans uneven halves, the split time calculator handles any distance, and the running pace calculator works out pace from a distance and time you have run.
Frequently asked questions
What pace do I need for a 4 hour marathon?
A marathon is 42.195 km. 4:00:00 is 14,400 seconds, and 14,400 ÷ 42.195 = 341.3 seconds per km, which is 5:41 per km or 9:09 per mile.
What is a negative split in a marathon?
A negative split means running the second half faster than the first. For a 4:00:00 goal and a 120 second difference, the halves are 2:01:00 and 1:59:00, about 5:44 and 5:38 per km.
How are the 5 km splits calculated?
They assume a perfectly even pace: your pace per km multiplied by the distance. At 5:41 per km, 5 km is reached at 28:26 and 10 km at 56:53. Real races need adjusting for hills and aid stations.
How do I convert my pace per km to per mile?
Multiply the seconds per km by 1.609344. 341.3 seconds per km is 549.2 seconds per mile, or 9:09.
What pace is a 5 hour marathon?
A 5:00:00 marathon is 18,000 s over 42.195 km, which is 7:07 per km or 11:27 per mile. The halfway point should come at about 2:30:00 and the 30 km mark at 3:33:18.
What pace is a 3 hour 30 minute marathon?
3:30:00 is 12,600 s over 42.195 km, or 4:59 per km and 8:01 per mile. The halfway point at 21.1 km should come in around 1:45:00.
What pace do I need to run a marathon in under 3 hours?
A 3:00:00 marathon needs 4:16 per km, or 6:52 per mile, held for the whole race. Even a slower 4:20 per km pace would finish in about 3:03.