🌬️ Attic Ventilation Calculator
Attic size and the rule
Attic length
Attic width
…or attic floor area directly
(use this instead of length × width if you know it)
Ventilation rule
1 / 150 — the standard reference rule
1 / 300 — where the code's conditions are met
Calculate ventilation
Calculator by
CalcCoverage
— free DIY & home-improvement calculators