Running pace·5:21 /km
5:21
/km · 11.21 km/h

5:21 per km — marathon in 3:45:45, 11.21 km/h

Running 5:21 per kilometre is 11.21 km/h. Hold it and the half comes in at 1:52:52, the marathon at 3:45:45.

Finish times

These assume you hold the pace from gun to tape. Most runners drift slower in the second half, so leave a margin when setting a target.

5K
26:45
10K
53:30
Half
1:52:52
Marathon
3:45:45
Speed
11.21 km/h
Metres per second
3.115 m/s
Pace per mile
8:37
One lap (400 m)
2:08

What this pace breaks

The cut-offs are tighter than they look: a sub-4 marathon needs 5:41 per kilometre, and one second slower puts you over four hours.

sub-20 min 5K · nosub-25 min 5K · nosub-30 min 5K · yessub-50 min 10K · nosub-60 min 10K · yessub-100 min Half · nosub-2h Half · yessub-3h Marathon · nosub-3:30h Marathon · nosub-4h Marathon · yessub-5h Marathon · yes

Nearby paces

Pace per kmHalfMarathon
5:161:51:073:42:14
5:171:51:283:42:56
5:181:51:493:43:38
5:191:52:103:44:20
5:201:52:313:45:02
5:211:52:523:45:45
5:221:53:133:46:27
5:231:53:343:47:09
5:241:53:563:47:51
5:251:54:173:48:33
5:261:54:383:49:16

The half and the full are not round numbers

A marathon is 42.195 km and a half is 21.0975 km. Rounding to 42 km costs you about a minute at a 5:00 pace — small, but enough to miss a target.

How to read this

  • Pace is the time for one kilometre, so a smaller number means faster.
  • To get speed, divide 3600 by the pace in seconds: 300 s gives 12 km/h.
  • A finish time is simply the pace multiplied by the distance.
  • Mile pace is kilometre pace times 1.609344.

Frequently asked questions

Q. What marathon time does 5:21 per km give?

3:45:45. The half comes in at 1:52:52, the 10K at 53:30 and the 5K at 26:45.

Q. How fast is 5:21 per km in km/h?

11.21 km/h, or 3.115 metres per second.

Q. What is that per mile?

8:37, because a mile is 1.609344 km.

Q. And one lap of the track?

2:08 for 400 m.