Ceiling Fan Size Calculator
Choose the right ceiling fan for your room. Enter your room dimensions and ceiling height to get the recommended blade span, minimum CFM rating, and proper mounting type. Works for bedrooms, living rooms, kitchens, and outdoor spaces.
Enter Your Room Details
Full Breakdown
Room Area
Blade Span
Minimum CFM
Mount Type
Fans Needed
Blade Clearance
How to Use This Calculator
- Enter your room length and width in feet.
- Enter the ceiling height (standard is 8 ft).
- Click "Calculate Fan Size" for blade span, CFM, and mount recommendations.
- For rooms over 400 sq ft, the calculator recommends multiple fans.
- Blade tips should be at least 18 inches from walls and 7 feet above the floor.
The Formula
Room Area = Length × Width
Blade span is matched to room area using industry guidelines:
- Up to 75 sq ft → 29–36 inch fan
- 76–144 sq ft → 36–42 inch fan
- 145–225 sq ft → 44–50 inch fan
- 226–400 sq ft → 50–54 inch fan
- Over 400 sq ft → 54–72 inch, or two fans
Minimum CFM ≈ Room Area × 1.0 to 2.0 (based on airflow need)
Target at least 1 CFM per sq ft for light airflow, 2 CFM per sq ft for heavy cooling. Mount type depends on ceiling height: flush mount for 7–8 ft, standard downrod for 8–9 ft, extended downrod for 10+ ft.