Four-hour marathon mile splits
A four-hour marathon averages about 9:09 per mile and 5:41 per kilometre. Twenty-six full mile rows reach roughly 3:58:00; the remaining 0.2188 mile takes about two minutes at the same pace and brings the sheet to 4:00:00.
The complete even-pace split sheet
| 1 | 1 mi | 1 mi | 9:09 | 9:09 |
| 2 | 2 mi | 1 mi | 9:09 | 18:18 |
| 3 | 3 mi | 1 mi | 9:09 | 27:28 |
| 4 | 4 mi | 1 mi | 9:09 | 36:37 |
| 5 | 5 mi | 1 mi | 9:09 | 45:46 |
| 6 | 6 mi | 1 mi | 9:09 | 54:55 |
| 7 | 7 mi | 1 mi | 9:09 | 1:04:05 |
| 8 | 8 mi | 1 mi | 9:09 | 1:13:14 |
| 9 | 9 mi | 1 mi | 9:09 | 1:22:23 |
| 10 | 10 mi | 1 mi | 9:09 | 1:31:32 |
| 11 | 11 mi | 1 mi | 9:09 | 1:40:41 |
| 12 | 12 mi | 1 mi | 9:09 | 1:49:51 |
| 13 | 13 mi | 1 mi | 9:09 | 1:59:00 |
| 14 | 14 mi | 1 mi | 9:09 | 2:08:09 |
| 15 | 15 mi | 1 mi | 9:09 | 2:17:18 |
| 16 | 16 mi | 1 mi | 9:09 | 2:26:28 |
| 17 | 17 mi | 1 mi | 9:09 | 2:35:37 |
| 18 | 18 mi | 1 mi | 9:09 | 2:44:46 |
| 19 | 19 mi | 1 mi | 9:09 | 2:53:55 |
| 20 | 20 mi | 1 mi | 9:09 | 3:03:05 |
An estimate, not medical advice. Body metrics are population averages and do not account for your individual circumstances. Speak to a clinician about anything that matters.
The marathon distance used is 42.195 kilometres, not a rounded 26 miles.
The final row is shorter because 42.195 kilometres is about 26.2188 miles.
Every checkpoint is calculated from total elapsed seconds, so rounded rows do not accumulate timing drift.
How it works
The formula
totalMetres = distanceKm x 1,000
totalSeconds = finishMinutes x 60
secondsPerMetre = totalSeconds / totalMetres
pacePerKm = secondsPerMetre x 1,000
pacePerMile = secondsPerMetre x 1,609.344
splitCount = ceiling(totalMetres / chosenSplitMetres)
checkpointDistance[n] = min(n x chosenSplitMetres, totalMetres)
checkpointTime[n] = totalSeconds x checkpointDistance[n] / totalMetres
Every checkpoint uses the unrounded totals. Displayed times are rounded only
after the checkpoint has been calculated.
What it assumes
- The sheet is an even mathematical pace from start to finish. It does not model hills, wind, congestion, aid stations, warm-up, fatigue or a deliberate negative split.
- Distance arrives in kilometres. The measurement-system switch converts miles at the input boundary, so the formula receives one base unit whichever control the visitor sees.
- One international mile is exactly 1,609.344 metres. A track-lap row is 400 metres; a real runner in an outside lane travels farther unless the start is staggered.
- Each displayed clock is rounded independently to the nearest second. Adding those rounded split labels can differ from the exact finish by a few seconds, so cumulative checkpoints come from the unrounded total instead.
- This is a planning aid, not medical or coaching advice. A target can be mathematically consistent and still be unsuitable for a particular runner.
Common questions
Why does multiplying the displayed mile pace not equal exactly four hours?
The displayed pace is rounded to a whole second, while every checkpoint is calculated from the unrounded ratio of total time to total distance. Repeatedly adding a rounded pace compounds that display rounding.
Does this plan include a faster or slower second half?
No. It is an even mathematical split sheet. Hills, weather, aid stations and fatigue can all make a real pacing plan deliberately uneven.
Sources
The full method, worked example and every assumption behind this figure are on Running Split Planner.