Enter the total open area and the total overall area into the Calculator. The calculator will evaluate the Open Area Percentage. 

Open Area Percentage Formula

OAP = OA / TA * 100


  • OAP is the Open Area Percentage (%)
  • OA is the total open area
  • TA is the total overall area

To calculate the Open Area Percentage, divide the total open area by the total area, then multiply by 100.

How to Calculate Open Area Percentage?

The following steps outline how to calculate the Open Area Percentage.

  1. First, determine the total open area. 
  2. Next, determine the total overall area. 
  3. Next, gather the formula from above = OAP = OA / TA * 100.
  4. Finally, calculate the Open Area Percentage.
  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.

total open area = 160

total overall area = 800