Enter the linear attenuation coefficient (1/cm) into the Half Value Layer Calculator. The calculator will evaluate the Half Value Layer.

## Half Value Layer Formula

The following two example problems outline the steps and information needed to calculate the Half Value Layer.

**HVL = .693/u**

Variables:

- HVL is the Half Value Layer (cm)
- u is the linear attenuation coefficient (1/cm)

## How to Calculate Half Value Layer?

The following steps outline how to calculate the Half Value Layer.

- First, determine the linear attenuation coefficient (1/cm).
- Next, gather the formula from above = HVL = .693/u.
- Finally, calculate the Half Value Layer.
- 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.

linear attenuation coefficient (1/cm) = .707

HVL = .693/u** **= ?