1:23 half marathon pace
A 1:23 half marathon is 3:56/km (6:20/mi), 15.3 km/h.
| Change | Time | Pace |
|---|---|---|
| −2:00 | 1:21:00 | 3:506:11 |
| −1:30 | 1:21:30 | 3:526:13 |
| −1:00 | 1:22:00 | 3:536:15 |
| −0:30 | 1:22:30 | 3:556:18 |
| Your target /km | ||
| +0:30 | 1:23:30 | 3:576:22 |
| +1:00 | 1:24:00 | 3:596:24 |
| +1:30 | 1:24:30 | 4:006:27 |
| +2:00 | 1:25:00 | 4:026:29 |
Arrow keys nudge the value. Hold Shift for bigger steps.
Finish times at 3:56 per km
| Distance | Finish time |
|---|---|
| 1K | 3:56 |
| 1 mile | 6:20 |
| 5K | 19:40 |
| 10K | 39:20 |
| 10 miles | 1:03:19 |
| Half marathon | 1:23:00 |
| Marathon | 2:46:00 |
| 50K | 3:16:42 |
Splits for a 1:23 half marathon
| km | Split | Elapsed |
|---|---|---|
| 1 | 3:56 | 3:56 |
| 2 | 3:56 | 7:52 |
| 3 | 3:56 | 11:48 |
| 4 | 3:56 | 15:44 |
| 5 | 3:56 | 19:40 |
| 6 | 3:56 | 23:36 |
| 7 | 3:56 | 27:32 |
| 8 | 3:56 | 31:28 |
| 9 | 3:56 | 35:24 |
| 10 | 3:56 | 39:20 |
| 11 | 3:56 | 43:17 |
| 12 | 3:56 | 47:13 |
| 13 | 3:56 | 51:09 |
| 14 | 3:56 | 55:05 |
| 15 | 3:56 | 59:01 |
| 16 | 3:56 | 1:02:57 |
| 17 | 3:56 | 1:06:53 |
| 18 | 3:56 | 1:10:49 |
| 19 | 3:56 | 1:14:45 |
| 20 | 3:56 | 1:18:41 |
| 21 | 3:56 | 1:22:37 |
| Final 0.098 km | 0:23 | 1:23:00 |
| Mile | Split | Elapsed |
|---|---|---|
| 1 | 6:20 | 6:20 |
| 2 | 6:20 | 12:40 |
| 3 | 6:20 | 19:00 |
| 4 | 6:20 | 25:20 |
| 5 | 6:20 | 31:39 |
| 6 | 6:20 | 37:59 |
| 7 | 6:20 | 44:19 |
| 8 | 6:20 | 50:39 |
| 9 | 6:20 | 56:59 |
| 10 | 6:20 | 1:03:19 |
| 11 | 6:20 | 1:09:39 |
| 12 | 6:20 | 1:15:59 |
| 13 | 6:20 | 1:22:18 |
| Final 0.109 mi | 0:42 | 1:23:00 |
What a 1:23 half marathon predicts
Estimate| Distance | Estimated time |
|---|---|
| 5K | 18:03 |
| 10K | 37:37 |
| 10 miles | 1:02:18 |
| Marathon | 2:53:03 |
These are estimates from the Riegel formula, T2 = T1 × (D2 ÷ D1)^1.06. They assume you’ve trained for the other distance, so treat them as a guide, not a promise.
From 1:10 to 1:25, the middle kilometres decide it
The opening kilometres feel controlled. The race is decided between 10 and 16 km, when holding pace starts to hurt and the finish is still a long way off.
Tempo runs and threshold intervals do most of the work, with a long run each week.
A gel around halfway is worth testing in training. Some runners race this fast without one; find out which suits you before race day.
Pace questions runners ask
- What pace do I need for a 1:23 half marathon?
- A 1:23 half marathon is 3:56/km (6:20/mi), 15.3 km/h, held for the whole race.
- What treadmill speed is 1:23 half marathon pace?
- Set the treadmill to 15.3 km/h or 9.5 mph to run 3:56/km (6:20/mi).
- Where should I be at halfway in a 1:23 half marathon?
- With even pacing you pass halfway in 41:30; with a negative split, a little later.
- What does a 1:23 half marathon predict for other distances?
- The Riegel formula estimates 18:03 for the 5K, 37:37 for the 10K, 1:02:18 for the 10-mile race, 2:53:03 for the marathon, assuming you’ve trained for each distance.