What Pace Do You Need for a 1:45 Half Marathon?
A 1:45 half marathon means holding 4:59/km or 8:01/mile for 21.1 km — breaking the 5:00/km barrier for the full distance. It's the classic next step after a sub-2, and the pace is quick enough that the last 5 km will tell you exactly how honest your first 10 km was.
Your goal
Average pace to hit it
Hold this pace from the gun and you cross the line right on 1:45:00.
The 1:45:00 target
Finish time
1:45:00
Average pace
4:59 /km
Checkpoints · 1:45:00 goal
| Distance | Block pace | Cumulative |
|---|---|---|
| 5 km | 4:59 | 24:53 |
| 10 km | 4:59 | 49:46 |
| 15 km | 4:59 | 1:14:39 |
| 20 km | 4:59 | 1:39:32 |
| Finish · 21.1 km | 4:59 | 1:45:00 |
How to pace it.
Slight negative split
Go through 10 km in about 49:45 to 50:00, feeling strong but restrained, then wind it up over the last 5 km. Half marathon pacing is less forgiving than marathon pacing — there's no easy cruise phase — so the difference between 4:55/km and 5:05/km early is the difference between finishing fast and hanging on.
What blows it up.
Opening at 4:40/km with the start-line surge. You pay for it from 15 km.
Racing the first 5 km against your watch instead of settling into rhythm.
Skipping fuel because 'it's only a half' — a gel around 40–50 minutes helps the last 5 km.
Running tangents badly and adding 200–300 m to the race.
Treating threshold training pace as race pace. 1:45 pace should feel slightly easier than tempo effort.
Adjust for the course
Same idea, different terrain.
At goal pace your checkpoints are roughly 24:53 at 5 km, 49:46 at 10 km, and 1:14:39 at 15 km, with halfway at 52:30.
On flat courses, even pacing works well; on rolling courses hold effort steady and accept a few seconds' drift either way.
Many races have a 1:45 pace group — good shelter on windy days, but check the early splits yourself.
If you've run a recent 10K, double it and add 5–6 minutes for a realistic half estimate at this level.
Half marathon pace — FAQ
What pace per km is a 1:45 half marathon?
4:59 per km. More precisely, 4:58.6/km over 21.0975 km.
What pace per mile is a 1:45 half marathon?
8:01 per mile over 13.1 miles.
What 10 km split do I need for a 1:45 half marathon?
Even pacing puts you through 10 km at 49:46. Aim for 49:45 to 50:00 with a controlled effort, then press over the last 5 km.
What 5K or 10K time suggests I can run a 1:45 half?
Roughly 22:50 for 5K or 47:30 for 10K, with regular long runs of 90 minutes or more.
Should I fuel during a 1:45 half marathon?
One gel around 40–50 minutes in is enough for most runners, taken with water. Practise it in training so it doesn't unsettle your stomach on race day.
Is a 1:45 half marathon a good time?
Yes — it's comfortably faster than the typical half marathon finish and a common gateway goal toward a 1:40 half or a sub-3:45 marathon.