Running Pace Calculator
Use this running pace calculator to turn a distance and a time into pace per kilometer, pace per mile and speed.
Your numbers
Want more like this in your inbox?
Field Notes that go deeper
The science behind the running pace calculator
Show the formulas, method and sources
Pace is the time you take per kilometer or per mile, while speed is how far you travel in an hour. The tool divides your total time by your distance, then shows the same run as a pace in both units and as a speed.
Formulas
Pace
Pace per km = total time / distance (km)Pace per mile = pace per km x 1.609344
Speed
Speed (km/h) = distance (km) / time (hours)Speed (mph) = speed (km/h) / 1.609344
How it works, step by step
- First, the calculator converts your distance to kilometers.
- Then it adds your hours, minutes and seconds into one total time.
- Next, it divides time by distance to find pace.
- Finally, it converts pace and speed to the other unit with the exact mile factor.
Worked example
A 5 km run in 25 minutes lasts 1,500 seconds. The pace is 1,500 / 5 = 300 seconds per kilometer, so the run is 5:00 per km or 8:03 per mile. The speed is 12 km/h, or 7.5 mph. If the pace held steady, a 10 km run at that pace would take 50:00.
Accuracy and limits
The mile is exactly 1,609.344 meters in the NIST conversion tables, so the factor between miles and kilometers carries no rounding error.
Pace and speed carry the same information. Speed in km/h is 3,600 divided by pace in seconds per kilometer, so 300 seconds per kilometer gives 12 km/h. The result is an average over the whole run. A lower pace number means a faster run, while the speed number rises.
Any error in your distance or time carries straight into the pace. Because time equals pace times distance, a 10-second change per kilometer moves a 5 km run by 50 seconds.
- Average pace hides hills, stops and fast or slow stretches.
- A route measured by a phone can differ from a marked course.
- This tool reports pace and does not predict race times, because real runs include warm-ups and tired stretches.
Sources
- National Institute of Standards and Technology. NIST Guide to the SI, Appendix B.8: factors for units listed alphabetically. Used for: The exact factor of 1,609.344 meters per mile.
Sources and math last reviewed: .
Questions people ask
How do I calculate running pace?
Divide your total time by your distance. If you ran 10 km in 50 minutes, the pace is 50 / 10 = 5 minutes per kilometer.
How do I convert min/km to min/mile?
Multiply the pace per kilometer by 1.609344. A pace of 5:00 per km becomes about 8:03 per mile.
What is a good running pace?
There is no single good pace. It depends on your fitness, the route and the day, so compare your own runs over time.
Why does my pace change from run to run?
Hills, weather, sleep and effort all change pace. If you compare runs of a similar length and conditions, trends become clearer.
Does the calculator work in miles?
Yes. When you switch to imperial, you enter miles and see pace per mile first, and both units still appear.
How do I use pace to plan a run?
Pick a pace you can hold, then multiply it by the distance to get a time. If you plan 8 km at 6:00 per km, the run takes 48 minutes. If you want a faster run, lower the pace a little at a time.
These calculators give general estimates for adults and are not medical advice. For decisions about your own health, talk with a doctor or a registered dietitian. How we write and check things