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Half Marathon Pace Calculator
The Half Marathon is 21.1 km (13.1 miles · 21.0975 km · 13.11 mi). At an even 5:00 /km (8:03 /mile) it takes 1:45:29 — that is 12 km/h (7.46 mph). Enter your own target time below.
Pace and speed are derived from one exact figure — your speed in metres per second — so min/km, min/mile, km/h and mph all agree and round-trip exactly. 1 mile = 1609.344 m.
Note: A half marathon is exactly half a marathon — 21.0975 km, about 13.109 miles.
Half Marathon pace chart — finish time by pace
Every even pace from 3:00 to 8:00 per kilometre, with the Half Marathon finish time it produces and the equivalent min/mile, km/h and mph.
| Pace /km | Pace /mile | Finish | km/h | mph |
|---|---|---|---|---|
| 3:00 | 4:50 | 1:03:18 | 20 | 12.4 |
| 3:15 | 5:14 | 1:08:34 | 18.5 | 11.5 |
| 3:30 | 5:38 | 1:13:50 | 17.1 | 10.7 |
| 3:45 | 6:02 | 1:19:07 | 16 | 9.94 |
| 4:00 | 6:26 | 1:24:23 | 15 | 9.32 |
| 4:15 | 6:50 | 1:29:40 | 14.1 | 8.77 |
| 4:30 | 7:15 | 1:34:56 | 13.3 | 8.28 |
| 4:45 | 7:39 | 1:40:13 | 12.6 | 7.85 |
| 5:00 | 8:03 | 1:45:29 | 12 | 7.46 |
| 5:15 | 8:27 | 1:50:46 | 11.4 | 7.1 |
| 5:30 | 8:51 | 1:56:02 | 10.9 | 6.78 |
| 5:45 | 9:15 | 2:01:19 | 10.4 | 6.48 |
| 6:00 | 9:39 | 2:06:35 | 10 | 6.21 |
| 6:15 | 10:04 | 2:11:52 | 9.6 | 5.97 |
| 6:30 | 10:28 | 2:17:08 | 9.23 | 5.74 |
| 6:45 | 10:52 | 2:22:24 | 8.89 | 5.52 |
| 7:00 | 11:16 | 2:27:41 | 8.57 | 5.33 |
| 7:15 | 11:40 | 2:32:57 | 8.28 | 5.14 |
| 7:30 | 12:04 | 2:38:14 | 8 | 4.97 |
| 7:45 | 12:28 | 2:43:30 | 7.74 | 4.81 |
| 8:00 | 12:52 | 2:48:47 | 7.5 | 4.66 |
Half Marathon splits — every kilometre
Even-pace splits for a 1:45:29 Half Marathon (5:00 /km): the cumulative time on the clock as you pass each kilometre marker.
| Marker | Split | Cumulative |
|---|---|---|
| 1 km | 5:00 | 5:00 |
| 2 km | 5:00 | 10:00 |
| 3 km | 5:00 | 15:00 |
| 4 km | 5:00 | 20:00 |
| 5 km | 5:00 | 25:00 |
| 6 km | 5:00 | 30:00 |
| 7 km | 5:00 | 35:00 |
| 8 km | 5:00 | 40:00 |
| 9 km | 5:00 | 45:00 |
| 10 km | 5:00 | 50:00 |
| 11 km | 5:00 | 55:00 |
| 12 km | 5:00 | 1:00:00 |
| 13 km | 5:00 | 1:05:00 |
| 14 km | 5:00 | 1:10:00 |
| 15 km | 5:00 | 1:15:00 |
| 16 km | 5:00 | 1:20:00 |
| 17 km | 5:00 | 1:25:00 |
| 18 km | 5:00 | 1:30:00 |
| 19 km | 5:00 | 1:35:00 |
| 20 km | 5:00 | 1:40:00 |
| 21 km | 5:00 | 1:45:00 |
| Finish (21.1 km) | 0:29 | 1:45:29 |
Half Marathon splits — every mile
The same 1:45:29 Half Marathon broken into one-mile splits (8:03 /mile).
| Marker | Split | Cumulative |
|---|---|---|
| 1 mi | 8:03 | 8:03 |
| 2 mi | 8:03 | 16:06 |
| 3 mi | 8:03 | 24:08 |
| 4 mi | 8:03 | 32:11 |
| 5 mi | 8:03 | 40:14 |
| 6 mi | 8:03 | 48:17 |
| 7 mi | 8:03 | 56:19 |
| 8 mi | 8:03 | 1:04:22 |
| 9 mi | 8:03 | 1:12:25 |
| 10 mi | 8:03 | 1:20:28 |
| 11 mi | 8:03 | 1:28:31 |
| 12 mi | 8:03 | 1:36:33 |
| 13 mi | 8:03 | 1:44:36 |
| Finish (13.1 mi) | 0:53 | 1:45:29 |
Half Marathon race-time predictions (Riegel estimate)
If your Half Marathon is worth 1:45:29, the Riegel formula estimates these equivalent times at other distances. These are estimates — real results depend on training, terrain and pacing.
| Distance | Predicted | Pace /km | Pace /mile |
|---|---|---|---|
| 1500 m | 6:24 | 4:16 | 6:52 |
| 3000 m | 13:21 | 4:27 | 7:09 |
| 1 Mile | 6:54 | 4:17 | 6:54 |
| 5K | 22:56 | 4:35 | 7:23 |
| 10K | 47:48 | 4:47 | 7:42 |
| 15K | 1:13:29 | 4:54 | 7:53 |
| 10 Mile | 1:19:10 | 4:55 | 7:55 |
| 30K | 2:33:12 | 5:06 | 8:13 |
| Marathon | 3:39:56 | 5:13 | 8:23 |
| 50K | 4:23:16 | 5:16 | 8:28 |
| 50 Mile | 7:15:58 | 5:25 | 8:43 |
| 100K | 9:08:54 | 5:29 | 8:50 |
| 100 Mile | 15:08:58 | 5:39 | 9:05 |
How Half Marathon pace is calculated
Pace is simply time ÷ distance. This page works it out exactly: it converts your Half Marathon into metres and your time into seconds, divides to get one speed in metres per second, then expresses that single number as min/km, min/mile, km/h and mph. Because a kilometre is exactly 1000 m and a mile exactly 1609.344 m, the four figures always agree and convert back to machine precision. Only the Riegel predictions above are estimates.
FAQ
What is a good Half Marathon time?
"Good" depends entirely on the runner, but a useful reference point is even pacing. At 5:00 /km (8:03 /mile) a Half Marathon takes 1:45:29. Enter your own target above and the calculator shows the exact pace and speed you need; the pace chart below lists finish times for every pace from 3:00 to 8:00 /km.
How many kilometres is a Half Marathon?
A Half Marathon is 21.1 km, which is 13.1 miles (21.0975 km · 13.11 mi). A mile is exactly 1609.344 m, so the conversion is exact rather than rounded.
What pace do I need for a 1:45:29 Half Marathon?
To finish a Half Marathon in 1:45:29 you hold 5:00 per kilometre, which is 8:03 per mile, or 12 km/h (7.46 mph). The split table below shows the clock at every kilometre and mile for that pace.
How are the Half Marathon race-time predictions calculated?
They use the Riegel formula, t₂ = t₁ × (d₂ / d₁)^1.06, a published 1977 model that scales a known result to another distance. It is an estimate, not a guarantee — real times depend on training, terrain, heat and pacing — and it is the only estimate on this page. Every pace and speed conversion here is exact.