🌬️ Bathroom Fan Calculator
Bathroom size
Room length
Room width
…or area directly
Ceiling height
Fixtures
(counted for bathrooms over 100 sq ft — the HVI fixture method)
Toilets
Showers
Bathtubs
Jetted tubs
Duct run
Short and smooth — under 10 ft, few elbows
Typical — 10 to 25 ft with elbows
Long or flexible duct — over 25 ft
Calculate fan size
Calculator by
CalcCoverage
— free DIY & home-improvement calculators