Attic Ventilation Calculator
Calculate the proper amount of attic ventilation needed. Get intake and exhaust vent requirements based on attic size.
Attic Details
Climate Zone:
Ventilation Type:
Net Free Vent Area (NFVA) Needed
720 sq in
(5.00 sq ft total ventilation)
Recommended Vents:
Intake Options
6 soffit vents
Standard 8" x 16" vents
Exhaust Option 1
20 ft ridge vent
Exhaust Option 2
8 box/roof vents
Power Ventilator Alternative:
1050 CFM minimum
Ventilation Standards
1:150 Rule (No Vapor Barrier)
1 sq ft ventilation per 150 sq ft of attic floor
1:300 Rule (With Vapor Barrier)
1 sq ft ventilation per 300 sq ft of attic floor
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Formula Source: Standard Mathematical References
by Various