How pace is calculated
Pace is the time it takes you to cover one unit of distance, written as minutes per mile (min/mi) or per kilometer (min/km).
For example, running a 10K (6.21 mi) in 50 minutes is an 8:03 min/mi pace, or 7.5 mph.
Race predictions with the Riegel formula
Engineer Peter Riegel published a formula in 1977 that predicts your time over another distance from a known result:
It works best between similar distances and when you've trained for the target race. For the marathon it tends to be optimistic for runners without high weekly mileage.
Standard race distances
| Race | Distance |
|---|---|
| 5K | 3.11 mi (5 km) |
| 10K | 6.21 mi (10 km) |
| Half marathon | 13.1 mi (21.0975 km) |
| Marathon | 26.2 mi (42.195 km) |
Frequently asked questions
What is a good running pace?
It depends on your level. Many recreational runners do easy runs between 9:00 and 11:00 min/mi. What matters is that most of your miles are at a pace where you can still talk.
How do I convert pace to mph?
Divide 60 by your pace in minutes. For example, 9:30 min/mi is 9.5 minutes, and 60 ÷ 9.5 = 6.3 mph.
Is the marathon prediction reliable?
Treat it as a guide. If your input race is a 5K or 10K and you haven't done long runs, add a few minutes to the predicted time.
What pace do I need for a sub-2-hour half marathon?
9:09 min/mi (5:41 min/km) or faster. For a sub-4-hour marathon you need 9:09 min/mi as well, and 8:01 min/mi for a sub-3:30.
Results are estimates for general information only and are not a substitute for advice from a doctor, registered dietitian or qualified coach.