What the pace calculator does
Enter a distance in kilometres or miles and the time it took, and the calculator returns your pace per kilometre, pace per mile and average speed. Pace — minutes per unit of distance — is how runners, walkers and cyclists talk about effort, because it maps directly onto race targets: “I need to hold 5:00/km to break 25 minutes for 5K.” The maths is simple but the unit juggling (minutes and seconds, km and miles) is exactly where mental arithmetic goes wrong.
The formulas
Pace (min per km) = total minutes ÷ distance in km
Pace (min per mile) = pace per km × 1.609344
Speed (km/h) = distance in km ÷ (total minutes ÷ 60)
Example: 10 km in 52:30 → 52.5 ÷ 10 = 5.25 min/km = 5:15 /km
5:15 × 1.609 = 8:27 /mile
10 ÷ 0.875 h = 11.4 km/hRemember that pace is expressed in minutes and seconds, not decimals: 5.25 min/km is 5 minutes 15 seconds, not 5:25. The calculator does that conversion for you.
Race time to pace reference
| Goal | Pace per km | Pace per mile |
|---|---|---|
| 5K in 30:00 | 6:00 | 9:39 |
| 5K in 25:00 | 5:00 | 8:03 |
| 5K in 20:00 | 4:00 | 6:26 |
| 10K in 60:00 | 6:00 | 9:39 |
| 10K in 50:00 | 5:00 | 8:03 |
| 10K in 45:00 | 4:30 | 7:15 |
| Half marathon in 2:00:00 | 5:41 | 9:09 |
| Half marathon in 1:45:00 | 4:59 | 8:01 |
| Marathon in 4:00:00 | 5:41 | 9:09 |
| Marathon in 3:30:00 | 4:59 | 8:01 |
| Marathon in 3:00:00 | 4:16 | 6:52 |
Half marathon is 21.0975 km (13.109 miles); marathon is 42.195 km (26.219 miles).
Using pace in training
- Easy runs — 60–90 seconds per km slower than 10K race pace; you should be able to talk in full sentences.
- Tempo / threshold — roughly the pace you could hold for an hour; about 15–25 s/km slower than 10K pace.
- Intervals — 5K pace or faster for 400 m–1 km repeats with recovery jogs.
- Long runs — at easy pace; the point is time on feet, not speed.
- Negative split — running the second half of a race faster than the first. Most personal bests are set this way; going out too fast is the most common racing mistake.
Walking and cycling
The same arithmetic applies. A brisk walk is about 9–10 min/km (6–6.5 km/h); a moderate cycling pace is 2:30–3:00 per km (20–24 km/h). Treadmills usually display speed rather than pace — 10 km/h is 6:00/km, 12 km/h is 5:00/km — and the calculator's speed output makes that conversion easy.
Why watch pace and race pace differ
- GPS watches typically read 1–3% long on a certified course because of weaving and signal noise, so the watch shows a slightly faster pace than the official result.
- Hills, wind and heat all slow pace at the same effort; a target pace set on a flat cool day needs adjusting.
- Race distances are measured on the shortest possible line; most runners cover more.