Pace vs speed
Pace is time per unit distance (for example, 5:30 per km). Speed is distance per unit time (for example, 10.9 km/h). Runners usually think in pace; cyclists in speed.
Pace = Time ÷ Distance Time = Pace × Distance Distance = Time ÷ Pace
Enter any two of the three and the calculator solves for the third, then shows the speed as well.
Popular distances
- 5K — 5 km (3.1 miles)
- 10K — 10 km (6.2 miles)
- Half marathon — 21.0975 km (13.1 miles)
- Marathon — 42.195 km (26.2 miles)
Calculating pace by hand
Example: you want to run a half marathon in 1:55:00.
- Convert the time to seconds: 1 × 3,600 + 55 × 60 = 6,900 s.
- Divide by the distance: 6,900 ÷ 21.0975 = 327 s per km.
- Convert back to minutes: 327 s = 5:27 per km.
- For miles, multiply by 1.609344: 327 × 1.609344 ≈ 526 s, or 8:46 per mile.
- Speed: 21.0975 ÷ 1.9167 hours = 11.01 km/h.
Solving the other way works the same. At 6:00 per km, 45 minutes of running covers 2,700 ÷ 360 = 7.5 km. At 10:00 per mile, a marathon takes 26.219 × 600 seconds = 4:22:11.
Race pace chart
| Pace per km | Pace per mile | 5K | 10K | Half marathon | Marathon |
|---|---|---|---|---|---|
| 4:00 | 6:26 | 20:00 | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 | 7:15 | 22:30 | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 | 8:03 | 25:00 | 50:00 | 1:45:29 | 3:30:59 |
| 5:30 | 8:51 | 27:30 | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 | 9:39 | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 | 10:28 | 32:30 | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 | 11:16 | 35:00 | 1:10:00 | 2:27:41 | 4:55:22 |
| 7:30 | 12:04 | 37:30 | 1:15:00 | 2:38:14 | 5:16:28 |
Using pace in training and on race day
- Expect your watch to disagree a little. GPS distance can drift from the measured course, especially among tall buildings or under trees, so race results and watch pace rarely match exactly.
- Start no faster than goal pace. Running the first few kilometers well ahead of plan usually costs more time later than it saves.
- Hills and heat slow you down. Judge effort on those days rather than chasing the number.
- Most easy runs should feel easy. Use goal pace for specific workouts and races, not every outing.