2:38 per km — marathon in 1:51:07, 22.78 km/h

Running 2:38 per kilometre is 22.78 km/h. Hold it and the half comes in at 55:33, the marathon at 1:51:07.

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: 13:10
10K: 26:20
Half: 55:33
Marathon: 1:51:07

Speed: 22.78 km/h
Metres per second: 6.329 m/s
Pace per mile: 4:14
One lap (400 m): 1:03

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

Nearby paces

Pace per km	Half	Marathon
2:33	53:48	1:47:36
2:34	54:09	1:48:18
2:35	54:30	1:49:00
2:36	54:51	1:49:42
2:37	55:12	1:50:25
2:38	55:33	1:51:07
2:39	55:55	1:51:49
2:40	56:16	1:52:31
2:41	56:37	1:53:13
2:42	56:58	1:53:56
2:43	57:19	1:54:38

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 2:38 per km give?

1:51:07. The half comes in at 55:33, the 10K at 26:20 and the 5K at 13:10.

Q. How fast is 2:38 per km in km/h?

22.78 km/h, or 6.329 metres per second.

Q. What is that per mile?

4:14, because a mile is 1.609344 km.

Q. And one lap of the track?

1:03 for 400 m.