How running pace is calculated
Pace is how long it takes you to cover one mile (or one kilometer), and it’s your total time divided by your distance. Run 3 miles in 30 minutes and your pace is 10:00 per mile.
A 5K in 30:00 works out to a 9:39 mile pace, or 6:00 per kilometer. Speed is the same thing flipped around: 60 divided by your pace in minutes, which here is 6.21 mph.
Goal paces for the marathon
Switch to “Find finish time,” enter the distance and the pace you plan to hold, and the calculator gives you your finish time:
| Pace per mile | Marathon finish |
|---|---|
| 8:00 | 3:29:45 |
| 9:09 | 3:59:54 |
A marathon is 26.2 miles, so a few seconds per mile add up: that 9:09 pace clears four hours by just six seconds.
Predicting your race times
From one recent race, the calculator estimates your time at the other classic distances with Riegel’s formula:
T2 = T1 × (D2 ÷ D1)^1.06
The 1.06 exponent accounts for slowing down as races get longer. From a 30-minute 5K it predicts:
- 10K: 1:02:33.
- Half marathon: 2:18:00.
- Marathon: 4:47:44.
Treat the marathon number as a best case. Without long runs of 16 to 20 miles in your training, expect to be slower.
Using pace in training
- Easy runs should feel conversational, well slower than race pace.
- Tempo runs and intervals are where you run at or faster than race pace.
- If you run to lose weight, estimate your daily needs with the calorie calculator.
Checking where you stand on weight? The BMI calculator gives your healthy range.