Enter the previous week’s mileage and the percentage increase into the calculator to determine the new weekly mileage. This calculator can also evaluate any of the variables given the others are known.

## 10 Percent Rule Running Formula

The following formula is used to calculate the new weekly mileage based on the 10 Percent Rule.

NM = WM + (WM * 0.10)

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 will give the new weekly mileage that adheres to the 10 Percent Rule, helping to minimize the risk of injury and allowing the body to adapt to the increased physical stress.

## What is a 10 Percent Rule Running?

The 10 Percent Rule in running is a guideline often used to increase distance or duration safely and effectively. It suggests that a runner should not increase their weekly mileage by more than 10 percent over the previous week. This gradual increase helps to minimize the risk of injury and allows the body to adapt to the increased physical stress.

## 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