Race Shape › Calculators › Running pace calculator › Sub-1:45 half marathon pace
Goal paceSub-1:45 half marathon pace
To run a sub-1:45 half marathon you need to average 4:59 per kilometre — 8:01 per mile, 12.1 km/h — and reach halfway in 52:30. Sub-1:45 needs a 10 km around 47 minutes and the endurance to hold just under 5:00/km.
Even-pace splits
| Distance | Clock |
|---|---|
| 5 km | 24:53 |
| 10 km | 49:46 |
| 15 km | 1:14:39 |
| 20 km | 1:39:31 |
| 21.1 km | 1:44:59 |
The fitness behind a sub-1:45 half marathon
A sub-1:45 half marathon is a VDOT of about 42.6. The same fitness, trained for each distance, runs:
| 5 km | 22:50 (4:34/km) |
|---|---|
| 10 km | 47:22 (4:44/km) |
| Marathon | 3:37:50 (5:10/km) |
So a 10 km in about 47:22 is the clearest sign you are ready. If your recent 10 km is well slower than that, the goal is still on — it needs a block, not a hopeful race day.
Training paces for it
| Easy | 5:49–6:39/km at the coast · 6:18/km or slower in Johannesburg |
|---|---|
| Threshold | 4:56/km · 5:20/km in Johannesburg |
| Intervals | 4:27/km · 4:50/km in Johannesburg |
At altitude
The same fitness is slower high up. Raced at about 1 680 m, a sub-1:45 half marathon effort comes out near 1:53:16; to break 1:45:00 up there you need fitness worth about 1:37:21 at the coast. Gauteng runners chasing this time are best off choosing a coastal race.
The sub-1:45 half 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-1:45 half marathon plan — free to buildSee your whole block before you pay.
Common questions
What pace is a sub-1:45 half marathon?
4:59 per kilometre, or 8:01 per mile.
What 10 km time shows I can run a sub-1:45 half marathon?
About 47:22 — the same fitness, trained for that distance.
How fast should easy runs be when training for a sub-1:45 half marathon?
No faster than 5:49/km at sea level, or 6:18/km in Johannesburg. Slower is fine.
Can I run a sub-1:45 half marathon in Johannesburg?
It is harder: at around 1 680 m the same effort is about 8% slower, so you need fitness worth about 1:37:21 at the coast.
How long does it take to train for a sub-1:45 half 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.