Ceiling Fan CFM & Blade Span Sizer calculates the recommended fan blade diameter in inches, minimum airflow Cubic Feet per Minute (CFM), and downrod extension lengths based on room dimensions and ceiling height.

### Ceiling Fan Sizing Guidelines Proper blade span ensures adequate room air circulation without creating excessive blade drag or motor hum: - **Room Area Multipliers:** - *Under 100 sq ft (small bedrooms, laundry):* 36" to 42" blade span, 2,500+ CFM. - *100 to 144 sq ft (standard bedrooms, home offices):* 44" to 50" blade span, 3,500+ CFM. - *145 to 300 sq ft (master bedrooms, living rooms):* 52" to 56" blade span, 5,000+ CFM. - *Over 300 sq ft (great rooms, open floorplans):* 60" to 72" blade span (or dual 52" fans), 6,500+ CFM. - **Downrod Sizing for Clearance:** Fan blades perform most efficiently when positioned 8.0 to 8.5 feet above the finished floor. For ceilings over 9 feet, calculate downrod length as: $$\text{Downrod Length (inches)} = (\text{Ceiling Height (ft)} - 8.5) \times 12$

### Worked Numeric Example Suppose a homeowner equips a 14 ft × 14 ft bedroom with 9-foot ceilings: - **Floor Area:** $14 \times 14 = 196\text{ sq ft}$. - **Recommended Blade Span:** 52" to 56" diameter. - **Minimum Airflow:** 5,000+ CFM rating. - **Mounting Configuration:** A 9-foot ceiling uses a standard flush mount or short 4-inch downrod to maintain the 8.5-foot blade clearance elevation.

### Client-Side Processing Note All fan sizing rules evaluate locally in your web browser. No room dimensions, floor plans, or home specifications are sent to any remote server.