Upgrading your bathroom vent fan but don’t know what size you need? Tired of sweating walls? Use our online vent fan cubic feet per minute (CFM) calculator to find out how many cubic feet per minute your fan should be! Don’t let moisture ruin your beautiful new bathroom. Calculate how big your fan should be and keep your bathroom walls safe from unnecessary water damage.
Bathroom vent fans serve an important function by removing humid air from your home to prevent mold and mildew from forming. Vent fans are rated by the number of cubic feet of air they move per minute (CFM), and it’s important to buy a large enough fan for the size of your bathroom. That’s why we developed this handy bathroom vent fan CFM calculator!
Use our handy online calculator to see what size vent fan you need for your home. Simply enter the dimensions of your bathroom in the calculator below to determine the minimum size vent fan you need for the bathroom in your home.
When installing a vent fan, make sure there’s at least a 1/2″ gap under the bathroom door to allow fresh air to enter the room when the fan is running. Run the fan for 15 to 20 minutes after showering or bathing to expel all the excess moisture.
Bathroom Vent Fan CFM (cubic feet per minute) calculator
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