Roof Venting & NFVA Estimator
Calculate required Net Free Vent Area (NFVA) in sq ft and sq inches for soffit intake and ridge exhaust.
Required NFVA Results
5.0 Sq Ft
Total Net Free Vent Area Required (720 Sq Inches)
Soffit Intake Vent Area (50%): 360 Sq In (2.5 Sq Ft)
Ridge Exhaust Vent Area (50%): 360 Sq In (2.5 Sq Ft)
Estimated Soffit Vents (9 sq in ea): 40 Vents