To break 4:00:00 in the marathon you need to average 5:41 per kilometer or 9:09 per mile. That is the whole answer in one line. The rest of this page explains how much margin those numbers actually give you, what your watch should read at every marker, and whether your current fitness supports the goal.
The exact 4 hour marathon pace
A marathon is 42.195 km. Four hours is 14,400 seconds. Divide one by the other and the strict line is 341.27 seconds per kilometer, or 5:41.27/km. In miles (26.2188 of them), it is 9:09.23 per mile.
The decimals matter because watches and pace bands show whole seconds, and whole seconds hide the result:
- Run a flat 5:41/km for the whole race and you finish in 3:59:48. Twelve seconds to spare.
- Run a flat 5:42/km and you finish in 4:00:31. Thirty-one seconds over.
- Run a flat 9:09/mile and you finish in 3:59:54. Six seconds to spare.
- Run a flat 9:10/mile and you finish in 4:00:20. Twenty seconds over.
So the usable pace is 5:41/km or 9:09/mile, and nothing slower. The margin on 9:09/mile is small enough that most people targeting sub-4 in miles should think of 9:05 as the number on the watch, not 9:09. More on that buffer in the race-day section below.
4 hour marathon splits by kilometer
Every marker at a perfectly even 5:41.27/km. Times are elapsed from the gun, rounded to the nearest second.
| Marker | Elapsed time |
|---|---|
| 5 km | 28:26 |
| 10 km | 56:53 |
| 15 km | 1:25:19 |
| 20 km | 1:53:45 |
| Half (21.0975 km) | 2:00:00 |
| 25 km | 2:22:12 |
| 30 km | 2:50:38 |
| 35 km | 3:19:05 |
| 40 km | 3:47:31 |
| Finish (42.195 km) | 4:00:00 |
The halfway number is the one to memorize. At even pace, sub-4 means a 2:00:00 half, so if you pass the half-marathon mat at 1:59:xx you are on the line, not under it.
4 hour marathon splits by mile
The same race at 9:09.23 per mile.
| Mile marker | Elapsed time |
|---|---|
| 1 | 9:09 |
| 5 | 45:46 |
| 10 | 1:31:32 |
| Half (13.11 mi) | 2:00:00 |
| 15 | 2:17:18 |
| 20 | 3:03:05 |
| 25 | 3:48:51 |
| Finish (26.22 mi) | 4:00:00 |
Mile 20 at 3:03 is the other number worth writing on your hand. If you reach it at 3:03 or faster with the legs still working, the final 10 km at 9:09/mile brings you home with margin.
Pacing bands: what each pace gets you
Whole-second paces around the 4-hour line, run evenly from start to finish. This is the table to use when deciding what the watch should actually display.
| Pace per km | Pace per mile | Half split | Marathon finish | Versus 4:00:00 |
|---|---|---|---|---|
| 5:35 | 8:59 | 1:57:48 | 3:55:35 | 4:25 under |
| 5:38 | 9:04 | 1:58:51 | 3:57:42 | 2:18 under |
| 5:41 | 9:09 | 1:59:54 | 3:59:48 | 0:12 under |
| 5:44 | 9:14 | 2:00:58 | 4:01:55 | 1:55 over |
| 5:47 | 9:18 | 2:02:01 | 4:04:02 | 4:02 over |
| 5:50 | 9:23 | 2:03:04 | 4:06:08 | 6:08 over |
Three seconds per kilometer is the difference between 3:57:42 and 3:59:48, and another three seconds is the difference between sub-4 and 4:01:55. A sub-4 plan with no buffer is a 4:01 plan on any day the course, the weather, or your stomach is not perfect. Most runners who break 4 for the first time do it by holding 5:36–5:39/km, not 5:41.
Nearby goals: 3:45 to 4:30
If your fitness says 4:00 is a stretch, or if you are already past it, here are the neighbouring targets with the exact pace each one requires. Paces are rounded to the whole second; the strict value is in brackets where rounding would cost you.
| Goal time | Pace per km | Pace per mile | Half split | 30 km split |
|---|---|---|---|---|
| 3:45:00 | 5:20 (5:19.94) | 8:35 (8:34.90) | 1:52:30 | 2:39:58 |
| 3:50:00 | 5:27 | 8:46 | 1:55:00 | 2:43:32 |
| 3:55:00 | 5:34 | 8:58 (8:57.78) | 1:57:30 | 2:47:05 |
| 4:00:00 | 5:41 | 9:09 | 2:00:00 | 2:50:38 |
| 4:05:00 | 5:48 | 9:21 (9:20.67) | 2:02:30 | 2:54:11 |
| 4:10:00 | 5:55 | 9:32 | 2:05:00 | 2:57:45 |
| 4:15:00 | 6:03 (6:02.60) | 9:44 (9:43.55) | 2:07:30 | 3:01:18 |
| 4:30:00 | 6:24 (6:23.93) | 10:18 (10:17.88) | 2:15:00 | 3:11:58 |
Note the rounding traps. A 3:45 marathon is 5:19.94/km, so a flat 5:20/km finishes at 3:45:02. A 4:30 marathon is 6:23.93/km, so a flat 6:24/km finishes at 4:30:03. In every case, round the watch pace down, never up. The full table from 2:48 to 4:55 is in the marathon pace chart.
Who is a sub-4 marathon realistic for?
Roughly a third of marathon finishers at big-city races break 4 hours, which makes it the single most common goal in the sport and a genuinely good time for a recreational runner. For a fuller breakdown by age and gender, see average marathon time.
The honest predictor is a recent race, not a feeling. Using Riegel's formula, T2 = T1 × (D2 / D1)^1.06, with D1 and D2 as the race distances, a half marathon converts to a marathon by a factor of 2.085 and a 10K by a factor of 4.60. Applied to the usual benchmarks:
| Recent race | Riegel marathon prediction | Verdict for sub-4 |
|---|---|---|
| Half marathon 1:45:00 | 3:38:55 | Comfortable |
| Half marathon 1:50:00 | 3:49:21 | Realistic with proper marathon training |
| Half marathon 1:52:00 | 3:53:31 | Possible, little margin |
| Half marathon 1:55:00 | 3:59:46 | On the line; a 1:55:07 half predicts exactly 4:00:00 |
| 10K 48:00 | 3:40:49 | Comfortable |
| 10K 50:00 | 3:50:01 | Realistic with proper marathon training |
| 10K 52:00 | 3:59:13 | On the line; a 52:10 10K predicts exactly 4:00:00 |
A caveat on the formula: Riegel assumes you are trained for the longer distance. The 1.06 exponent is well matched to runners who have done the long runs. If your longest run is 25 km, the real-world conversion from half to marathon is closer to 2.15 or 2.2, and a 1:50 half becomes a 3:56–4:02 marathon, not 3:49. The 10K prediction is less reliable still, because 10K speed says little about how you handle three and a half hours on your feet.
So the working rule: a half marathon of about 1:50 or faster, or a 10K of about 50 minutes or faster, backed by a full marathon build, predicts a sub-4. A 1:55 half gets you to the line with nothing to spare.
Training benchmarks for a 4 hour marathon
There is no single sub-4 plan, but the runners who get there tend to share a few markers in the final two months of a build:
- Long runs of 32–35 km. At least two or three of them, with the longest around three to four weeks out from race day. Time on feet of 3:00–3:30 at an easy pace is what prepares the legs for the final 10 km.
- Weekly volume typically 50–70 km. Some people break 4 on less, but the runners who do it comfortably usually sit in this range for most of the build, across four to five runs a week.
- Marathon-pace segments inside long runs. For example, 10–16 km at 5:35–5:41/km in the second half of a 30 km run. If you cannot hold goal pace for 15 km at the end of a long run three weeks out, the chart pace is not yet honest.
- Easy days that are actually easy. Most of the 50–70 km should be run at 6:30–7:15/km. Goal pace should feel controlled in training, not like a race.
The point of the marathon-pace work is calibration. By race week you should know what 5:41/km feels like without looking at the watch. For the final seven days, see the race-week taper guide.
Race-day strategy for sub-4
Run even, or slightly negative. The ideal halfway split for a 4:00 goal is 1:58:00–1:59:00, not 1:55. Going through halfway in 1:55 means you ran 5:27/km for 21 km, and a runner whose fitness is a 4:00 marathon will pay for that between 30 and 38 km. A 1:58:30 first half leaves a second half of 2:01:30, which is 5:45.5/km, a pace that is entirely holdable if you were patient early. A 1:55 first half leaves 2:05:00 for the second half, which sounds easy and almost never is. The full reasoning is in how to pace a marathon.
Your watch pace must be faster than chart pace. GPS watches measure a marathon course long, usually by 0.3–0.6%, because you cannot run the measured tangents through 20,000 people and the satellite signal wanders in cities. At 0.5% that is about 211 extra meters and 72 seconds at goal pace. So to finish in 4:00:00 on the clock, the watch needs to read roughly 5:39–5:40/km (or 9:05–9:07/mile) as the average, not 5:41. Use the official kilometer markers as the truth and treat the watch as a guide.
Bank nothing, lose nothing. The pacing-bands table shows the cost of each second per kilometer. A plan at 5:38/km with a strong finish gives you 3:57:42 and a margin of two minutes for a slow aid station or a windy bridge. That is the plan, not 5:41 with no margin.
Fuel early. Sub-4 is three and a half to four hours of running, long enough to empty glycogen stores without carbohydrate intake. Start gels or drink by 45 minutes and keep taking carbohydrate every 20–30 minutes. See running nutrition basics.
FAQ
What pace is a 4 hour marathon?
A 4 hour marathon is 5:41 per kilometer (strictly 5:41.27/km). Running a flat 5:41/km finishes in 3:59:48; a flat 5:42/km finishes in 4:00:31. So 5:41/km is the slowest whole-second pace that breaks 4 hours.
What pace is a 4 hour marathon per mile?
A 4 hour marathon is 9:09 per mile (strictly 9:09.23/mile). A flat 9:09/mile finishes in 3:59:54, and 9:10/mile finishes in 4:00:20, so the margin at 9:09 is only six seconds. Most runners should target 9:05–9:07/mile on the watch.
Is a 4 hour marathon good?
Yes. Roughly a third of marathon finishers break 4 hours, so a sub-4 puts you in the faster portion of the field at most big-city races and well ahead of the typical finish time, which sits closer to 4:30. It generally requires months of structured training with long runs over 30 km.
What half marathon time predicts a sub-4 marathon?
Using Riegel's formula, a 1:55:07 half marathon predicts exactly 4:00:00, so a half of about 1:50 or faster gives a realistic margin. A 1:50 half predicts 3:49:21 and a 1:52 half predicts 3:53:31, assuming full marathon training. A 50:00 10K predicts 3:50:01.
Further reading
- Marathon pace chart: finish times for every pace
- Average marathon time by age and gender
- 3 hour marathon pace: the exact splits to break 3:00
- Race-week taper: the final 7 days before a marathon
- Running nutrition basics
Build your sub-4 splits
The tables above assume a perfectly even race. Real courses have hills, headwinds, and aid stations. Model your own 4-hour marathon splits, kilometer by kilometer, at runpace.co — set a slight negative split, bank a GPS buffer, and take the plan to the start line.