Fan CFM Calculator: Calculate Airflow for Ventilation & Fan Sizing

Calculate Required Fan CFM for Your Space

Typical ACH: Living spaces (3-6), Bathrooms (8-12), Kitchens (10-15), Workshops (20-30).

Use our free Fan CFM Calculator to determine the ideal Cubic Feet per Minute (CFM) needed for optimal ventilation in any room. Simply input your room's dimensions and desired Air Changes Per Hour (ACH) to calculate the exact airflow required for exhaust fans, range hoods, or whole-house systems. Ensure healthy indoor air quality and efficient air circulation.

Formula:

The Fan CFM Calculator uses the following formula:

1. Room Volume (V) = Length (L) × Width (W) × Height (H)

2. Required CFM = (Room Volume × Desired Air Changes Per Hour (ACH)) ÷ 60

Where:

  • L = Room Length in feet
  • W = Room Width in feet
  • H = Room Height in feet
  • ACH = Desired Air Changes Per Hour (typical values range from 3-6 for living spaces, 8-12 for bathrooms, 10-15 for kitchens, and up to 20-30 for workshops or specific applications).

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