Calculate next week’s running mileage with the 10 percent rule, work back to last week’s distance, or plan a multiweek schedule in miles or kilometers.
10 Percent Rule Running Formula
The following formula is used to calculate the new weekly mileage based on the 10 Percent Rule.
Variables:
- NM is the new weekly mileage (miles)
- WM is the previous week’s mileage (miles)
To calculate the new weekly mileage, multiply the previous week’s mileage by 0.10 (representing the 10 percent increase). Add this result to the previous week’s mileage. This gives the mileage after a 10 percent increase. It is an arithmetic reference, not a personalized training prescription or a proven injury-prevention threshold.
| Increase step | Previous mileage | 10% addition | Calculated mileage |
|---|---|---|---|
| Increase 1 | 20.00 mi | 2.00 mi | 22.00 mi |
| Increase 2 | 22.00 mi | 2.20 mi | 24.20 mi |
| Increase 3 | 24.20 mi | 2.42 mi | 26.62 mi |
| Increase 4 | 26.62 mi | 2.66 mi | 29.28 mi |
The table demonstrates successive 10% increases from 20 miles. In the multiweek calculator, Week 1 is the starting distance; later weeks increase by 10% unless an optional cutback is scheduled. Increases resume from the reduced distance after a cutback. The 25% long-run figures are reference values, not recommendations.
What Is the 10 Percent Rule for Running?
The 10 Percent Rule in running is a rule of thumb for increasing weekly distance gradually. It suggests limiting weekly mileage increases to 10 percent over the previous week. The calculator models that arithmetic; it does not establish that a particular increase is safe or will prevent injury.
How to Calculate 10 Percent Rule Running?
The following steps outline how to calculate the 10 Percent Rule Running using the formula: NM = WM + (WM * 0.10).
- First, determine the previous week’s mileage (WM) in miles.
- Next, calculate 10% of the previous week’s mileage by multiplying WM by 0.10.
- Add the result from step 2 to the previous week’s mileage (WM) to get the new weekly mileage (NM).
- Finally, calculate the new weekly mileage (NM).
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem:
Use the following variables as an example problem to test your knowledge.
Previous week’s mileage (WM) = 50 miles
Sources
Journal of Orthopaedic & Sports Physical Therapy. 2014;44(10):748. Running: How to Safely Increase Your Mileage.