Enter the total depth (ft) and the fraction of nitrogen into the Calculator. The calculator will evaluate the Equivalent Air Depth.

## Equivalent Air Depth Formula

EAD = (D + 33) * FN /.79 - 33

Variables:

- EAD is the Equivalent Air Depth (ft)
- D is the total depth (ft)
- FN is the fraction of nitrogen

To calculate Equivalent Air Depth, add 33 to the depth, multiply by the reaction of nitrogen over .79, then subtract 33 from the result.

## How to Calculate Equivalent Air Depth?

The following steps outline how to calculate the Equivalent Air Depth.

- First, determine the total depth (ft).
- Next, determine the fraction of nitrogen.
- Next, gather the formula from above = EAD = (D + 33) * FN /.79 – 33.
- Finally, calculate the Equivalent Air Depth.
- 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.

total depth (ft) = 130

fraction of nitrogen = 65