Self Speed
Running pace calculator
Runners think in pace — minutes per kilometre. Speedometers think in speed — kilometres per hour. They are the same information inverted, and the conversion is one division:
pace in min/km = 60 ÷ speed in km/h
So 12 km/h is exactly 5:00 per km. 10 km/h is exactly 6:00. Those two are worth memorising, because everything else can be estimated from them.
Speed to pace
| km/h | mph | min/km | min/mile |
|---|---|---|---|
| 6 | 3.7 | 10:00 | 16:06 |
| 7 | 4.3 | 8:34 | 13:48 |
| 8 | 5.0 | 7:30 | 12:04 |
| 9 | 5.6 | 6:40 | 10:44 |
| 10 | 6.2 | 6:00 | 9:39 |
| 11 | 6.8 | 5:27 | 8:47 |
| 12 | 7.5 | 5:00 | 8:03 |
| 13 | 8.1 | 4:37 | 7:26 |
| 14 | 8.7 | 4:17 | 6:54 |
| 15 | 9.3 | 4:00 | 6:26 |
| 16 | 9.9 | 3:45 | 6:02 |
| 18 | 11.2 | 3:20 | 5:22 |
| 20 | 12.4 | 3:00 | 4:50 |
Race times at each pace
What that pace produces over the standard distances, assuming you hold it evenly — which, over a marathon, almost nobody does.
| min/km | 5K | 10K | Half | Marathon |
|---|---|---|---|---|
| 7:30 | 37:30 | 1:15:00 | 2:38:14 | 5:16:28 |
| 6:40 | 33:20 | 1:06:40 | 2:20:39 | 4:41:18 |
| 6:00 | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 5:27 | 27:16 | 54:33 | 1:55:05 | 3:50:09 |
| 5:00 | 25:00 | 50:00 | 1:45:29 | 3:30:58 |
| 4:37 | 23:05 | 46:09 | 1:37:22 | 3:14:45 |
| 4:17 | 21:26 | 42:51 | 1:30:25 | 3:00:50 |
| 4:00 | 20:00 | 40:00 | 1:24:23 | 2:48:47 |
| 3:45 | 18:45 | 37:30 | 1:19:07 | 2:38:14 |
Pace does not hold across distances
Your sustainable pace drops as distance rises. A runner racing 5K at 5:00/km should expect roughly:
- 10K — 5:10 to 5:15/km
- Half marathon — 5:25 to 5:30/km
- Marathon — 5:45 to 6:00/km
Starting a marathon at half-marathon pace is the most common and most punishing mistake in distance running. The first 30 km feel fine. The last 12 do not.
Converting in your head
km/h to min/km: divide 60 by the speed. Anchor on 10 km/h = 6:00/km, then adjust — 12 km/h is a fifth faster, so 5:00.
min/km to min/mile: multiply by 1.609. A useful shortcut is add 60% — 5:00/km becomes roughly 8:03/mile.
Marathon shortcut: your marathon time in hours is roughly your pace in min/km multiplied by 0.703. At 6:00/km that gives 4.22 hours, or about 4:13.
Measuring pace on the run
GPS pace is noisy at the instant level. Position error of a few metres becomes a large apparent pace swing when sampled every second, which is why watches show you 4:30 one moment and 6:10 the next on steady effort.
Self Speed averages over 2.5 seconds to suppress that, and reports a moving average that excludes time spent stopped. See running speed tracker and average running speed.
Open the speedometer → Free, no install, works offline. Nothing leaves your device.