Sub 4 hour marathon pace
To break four hours you need to average 5:41 per kilometre, or 9:09 per mile, for 42.195 km. Hold exactly that on your watch and you will miss it.
5:41 /km
9:09 per mile
Why 5:41 on your watch finishes at 4:02
A marathon is measured along the shortest legal line. Nobody runs it. Weaving through a field, going wide at drink stations and cutting corners badly adds up, and a GPS watch commonly reads 42.6 to 43.0 km at the finish.
Hold exactly 5:41/km and cover 1% extra: 4:02:24. Every kilometre on target, and still outside four hours by two minutes.
Hold 5:37/km and cover the same 1% extra: 3:59:34.
Run about 5:37 per kilometre on the watch and the extra distance stops deciding your result.
Split times
The time to pass each marker. The first column is exact four hour pace; the second holds 5:37/km, the pace that still finishes under four hours after the usual extra distance.
| Marker | 4:00:00 pace | With margin, 5:37/km |
|---|---|---|
| 5 km | 28:26 | 28:05 |
| 10 km | 56:53 | 56:10 |
| 15 km | 1:25:19 | 1:24:15 |
| 20 km | 1:53:45 | 1:52:20 |
| Halfway, 21.1 km | 2:00:00 | 1:58:30 |
| 25 km | 2:22:12 | 2:20:25 |
| 30 km | 2:50:38 | 2:48:30 |
| 35 km | 3:19:05 | 3:16:35 |
| 40 km | 3:47:31 | 3:44:40 |
| Finish, 42.2 km | 4:00:00 | 3:57:00 |
Where sub 4 is usually lost
Almost never in the first half. It goes between 30 and 35 km, and the cause is a first 10 km run 10 to 15 seconds a kilometre too fast because the legs felt easy. Going out at 5:25 banks about three minutes and costs far more than that later. If you are within a minute of plan at halfway and still running 5:37s at 30 km, the race is yours.
Hold it without watching your wrist
Pace Coach is a free iPhone app that coaches pace by voice. Set the distance and a goal of 3:57:00, and it works out the pace for you, stays silent while you are on it, and says so the moment you drift too fast or too slow. It tells you your split at every kilometre, with the phone in your pocket and your music still playing.
Questions
What pace is a sub 4 hour marathon?
5:41 per kilometre or 9:09 per mile averages exactly four hours. Because most runners cover about 1 percent more than the measured course, aim for around 5:37 per kilometre on your watch.
What should my halfway split be for a sub 4 marathon?
1:59:48 at exact four hour pace, or 1:58:26 holding 5:37/km. Reaching halfway faster than 1:56 usually means the second half will be slower than the first by more than you gained.
Is 5:41 per km enough for a sub 4 marathon?
Only if your watch and the course agree exactly. With the usual 1 percent of extra distance, holding 5:41 per kilometre finishes at about 4:02:24.