Enter the total house area (ft^2) into the Flood Vent Size Calculator. The calculator will evaluate the Flood Vent Size. 

Flood Vent Size Formula

The following two example problems outline the steps and information needed to calculate the Flood Vent Size.

FVS = A 


  • FVS is the Flood Vent Size (square inches)
  • A is the total house area (ft^2) 

To calculate the flood vent size, simply take the total house area in ft^2, and make this value the flood vent size with units of inches squared.

How to Calculate Flood Vent Size?

The following steps outline how to calculate the Flood Vent Size.

  1. First, determine the total house area (ft^2). 
  2. Next, gather the formula from above = FVS = A .
  3. Finally, calculate the Flood Vent Size.
  4. 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 house area (ft^2) = 900

FVS = A  = ?