Enter the airflow rate (CFM) and the filter area (ft^2) into the Air to Cloth Ratio Calculator. The calculator will evaluate the Air to Cloth Ratio. 

Air to Cloth Ratio Formula

The following two example problems outline the steps and information needed to calculate the Air to Cloth Ratio.

ACR = AF / FA

Variables:

  • ACR is the Air to Cloth Ratio (CFM/ft^2)
  • AF is the airflow rate (CFM) 
  • FA is the filter area (ft^2) 

How to Calculate Air to Cloth Ratio?

The following steps outline how to calculate the Air to Cloth Ratio.


  1. First, determine the airflow rate (CFM). 
  2. Next, determine the filter area (ft^2). 
  3. Next, gather the formula from above = ACR = AF / FA.
  4. Finally, calculate the Air to Cloth Ratio.
  5. 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.

airflow rate (CFM) = 30

filter area (ft^2) = 2

ACR = AF / FA = ?