๐ Running Pace Calculator
Enter the distance you ran and the time it took, and this tool calculates your pace per kilometer, pace per mile, and average speed. It also shows predicted times for 5K, 10K, half marathon, and full marathon at the same pace. Handy for setting a race pace or reviewing your training log.
How to use
- Enter the distance you ran, in kilometers.
- Enter the time it took (hours, minutes, seconds).
- Your pace per km, pace per mile, and predicted times for common race distances are shown automatically.
How the calculation works
This tool calculates pace per kilometre, pace per mile and average speed (km/h) from a distance and time, and projects your times for 5 km, 10 km, half marathon and marathon at the same pace. Pace (min/km) = time (min) รท distance (km) Pace (min/mile) = pace (min/km) ร 1.609344 Speed (km/h) = distance (km) รท time (h) Projected time = pace ร race distance The half marathon is 21.0975 km and the marathon 42.195 km. Times are rounded to the nearest second.
Worked example
5 km in 25:00 Pace: 25 รท 5 = 5:00 per km Per mile: about 8:03 Speed: 5 รท (25 รท 60) = 12 km/h Projected times at the same pace 10 km: 50:00 Half marathon: 1:45:29 Marathon: 3:30:59
Things to be aware of
- Projections assume you hold the same pace. In practice pace usually drops over longer distances, so marathon times tend to be slower than projected.
- Methods such as Peter Riegel's formula (T2 = T1 ร (D2 รท D1)^1.06) account for that slowdown.
- GPS watch distances can be off in tunnels or among tall buildings.
FAQ
How are the predicted times calculated?
They're a simple projection assuming you could hold the same pace for 5K, 10K, a half marathon, or a full marathon. In reality, pace tends to be harder to sustain over longer distances, so treat these as rough estimates.
Can I use this with a treadmill's readout?
Yes, enter the distance and time shown on the treadmill display to calculate your pace the same way.
How is the mile-to-kilometer conversion done?
It uses 1 mile = 1.60934 km.