Roof Vent NFA Calculator
Calculate the net free area (NFA) of attic ventilation needed for a roof.
Required NFA
1,440 sq in
Sqft Equivalent
10.00
Code Ratio
1:150
Calculate the net free area (NFA) of attic ventilation needed for a roof.
Required NFA
1,440 sq in
Sqft Equivalent
10.00
Code Ratio
1:150