Sub 2 hour half marathon pace
To break two hours for 21.1 km you need to average 5:41 per kilometre, or 9:09 per mile. That is the number on every pace chart, and on its own it is not quite enough.
5:41 /km
9:09 per mile
Why 5:41 on your watch still misses
A half marathon is measured along the shortest line a runner could take: the inside of every corner. Nobody runs that line. Weaving past people, going wide on bends and crossing the road for a water table add distance, and it is normal to finish with your watch showing 1 to 2 percent more than 21.1 km.
Hold exactly 5:41/km on the watch and cover 1% extra: 2:01:06. Two hours gone by more than a minute, with every kilometre on target.
Hold 5:36/km and cover the same 1% extra: 1:59:20. That five seconds a kilometre is the whole margin.
So the pace to run is about 5:36/km on the watch, not 5:41. It is the difference between a plan that works on paper and one that works on the road.
Split times
The time to pass each kilometre marker. The first column is exact 2:00:00 pace; the second holds 5:36/km, the pace that still finishes inside the goal after the usual extra distance.
| Marker | 2:00:00 pace | With margin, 5:36/km |
|---|---|---|
| 1 km | 5:41 | 5:36 |
| 2 km | 11:23 | 11:11 |
| 3 km | 17:04 | 16:47 |
| 4 km | 22:45 | 22:22 |
| 5 km | 28:26 | 27:58 |
| 6 km | 34:08 | 33:34 |
| 7 km | 39:49 | 39:09 |
| 8 km | 45:30 | 44:45 |
| 9 km | 51:11 | 50:20 |
| 10 km | 56:53 | 55:56 |
| 11 km | 1:02:34 | 1:01:31 |
| 12 km | 1:08:15 | 1:07:07 |
| 13 km | 1:13:57 | 1:12:43 |
| 14 km | 1:19:38 | 1:18:18 |
| 15 km | 1:25:19 | 1:23:54 |
| 16 km | 1:31:00 | 1:29:29 |
| 17 km | 1:36:42 | 1:35:05 |
| 18 km | 1:42:23 | 1:40:41 |
| 19 km | 1:48:04 | 1:46:16 |
| 20 km | 1:53:45 | 1:51:52 |
| 21 km | 1:59:27 | 1:57:27 |
| Finish, 21.1 km | 2:00:00 | 1:58:00 |
Where sub 2 usually goes
Almost never in one bad kilometre. It goes in the first five, run 15 or 20 seconds a kilometre quicker than planned because the start is crowded, fresh and loud, and it is paid back between 15 and 18 km when the pace that felt easy stops feeling like anything you can hold.
The runners who break two hours tend to pass 10 km a little under 56:53 and then simply keep going. The ones who miss often passed 10 km in 55 minutes feeling brilliant.
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 1:58:00, and it works out 5:36/km 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 2 hour half marathon?
5:41 per kilometre or 9:09 per mile averages exactly two hours over 21.1 km. Because most runners cover about 1 percent more than the measured course, aim for around 5:36 per kilometre on your watch.
What should my 10K split be for a sub 2 half marathon?
56:53 at exact two hour pace. Running to a 1:58 finish for the margin puts you through 10 km in 55:56.
What should my 5K split be for a sub 2 half marathon?
28:26 at exact two hour pace, or 27:58 running to a 1:58 finish. Much quicker than that and the first 5 km is borrowing from the last 5.
How much margin should I leave for a sub 2 half marathon?
About 5 seconds per kilometre. It covers the 1 to 2 percent of extra distance most runners add by not running the tangents, which at two hour pace costs around 70 seconds.