Pace formula
Pace = time ÷ distance · Speed = distance ÷ time
A 5K in 25:00 is a pace of 5:00 per kilometer, or about 8:03 per mile. That is a speed of 12 km/h, or about 7.5 mph.
Race distances
| Race | Kilometers | Miles |
|---|
| 5K | 5 | 3.11 |
| 10K | 10 | 6.21 |
| Half marathon | 21.0975 | 13.1 |
| Marathon | 42.195 | 26.2 |
Using pace in training
- Easy runs are usually much slower than race pace. You should be able to talk in full sentences.
- Race pace practice teaches you how your goal pace feels.
- Negative splits, running the second half faster than the first, are a common race strategy.
- Plan to slow down a little for hills, heat and longer races.
Last reviewed October 2026.
Frequently asked questions
How do I calculate my running pace?
Divide your total time by the distance. Running 5 kilometers in 25 minutes is 25 ÷ 5 = 5 minutes per kilometer. In miles, 5 km is 3.11 miles, so the pace is about 8:03 per mile.
What is the difference between pace and speed?
Pace is time per distance, such as minutes per mile. Speed is distance per time, such as miles per hour. Runners usually talk in pace, while treadmills often show speed. The calculator shows both.
How long is a marathon?
A marathon is 42.195 km, or 26.2 miles. A half marathon is 21.0975 km, or 13.1 miles. A 5K is 3.1 miles and a 10K is 6.2 miles.
Can I predict my race time?
Enter a pace you can hold and the calculator shows finish times for common race distances at that pace. Keep in mind that most runners slow down over longer distances, so a pace you can hold for a 5K is usually faster than your marathon pace.
How do I enter my time?
Use hours:minutes:seconds, like 1:45:30, or minutes:seconds, like 25:00. A single number is read as minutes.