Race Shape › Calculators › Running pace calculator › Sub-3 hour marathon pace
Goal paceSub-3 hour marathon pace
To run a sub-3 hour marathon you need to average 4:16 per kilometre — 6:52 per mile, 14.1 km/h — and reach halfway in 1:30:00. Sub-3 is the marathon runner’s line in the sand: 4:15/km, a 10 km around 39 minutes, and a block of serious mileage.
Even-pace splits
| Distance | Clock |
|---|---|
| 5 km | 21:20 |
| 10 km | 42:39 |
| 15 km | 1:03:59 |
| 20 km | 1:25:19 |
| 21.1 km | 1:29:59 |
| 25 km | 1:46:38 |
| 30 km | 2:07:58 |
| 35 km | 2:29:18 |
| 40 km | 2:50:37 |
| 42.2 km | 2:59:59 |
The fitness behind a sub-3 hour marathon
A sub-3 hour marathon is a VDOT of about 53.5. The same fitness, trained for each distance, runs:
| 5 km | 18:48 (3:46/km) |
|---|---|
| 10 km | 38:59 (3:54/km) |
| Half marathon | 1:26:16 (4:05/km) |
So a half marathon in about 1:26:16 is the clearest sign you are ready. If your recent half marathon is well slower than that, the goal is still on — it needs a block, not a hopeful race day.
Training paces for it
| Easy | 4:51–5:33/km at the coast · 5:15/km or slower in Johannesburg |
|---|---|
| Threshold | 4:06/km · 4:27/km in Johannesburg |
| Intervals | 3:42/km · 4:01/km in Johannesburg |
At altitude
The same fitness is slower high up. Raced at about 1 680 m, a sub-3 hour marathon effort comes out near 3:14:10; to break 3:00:00 up there you need fitness worth about 2:46:52 at the coast. Gauteng runners chasing this time are best off choosing a coastal race.
The sub-3 hour marathon training plan lays out the weeks; a plan built from your own recent time says plainly whether the goal is on.
Build my sub-3 hour marathon plan — free to buildSee your whole block before you pay.
Common questions
What pace is a sub-3 hour marathon?
4:16 per kilometre, or 6:52 per mile.
What half marathon time shows I can run a sub-3 hour marathon?
About 1:26:16 — the same fitness, trained for that distance.
How fast should easy runs be when training for a sub-3 hour marathon?
No faster than 4:51/km at sea level, or 5:15/km in Johannesburg. Slower is fine.
Can I run a sub-3 hour marathon in Johannesburg?
It is harder: at around 1 680 m the same effort is about 8% slower, so you need fitness worth about 2:46:52 at the coast.
How long does it take to train for a sub-3 hour marathon?
It depends on the gap. Improving about 0.4% a week is a reasonable rate for a trained runner, so a 5% gap is roughly 12–13 weeks. The plan page works it out.