Measure the room length and width in feet
Multiply length by width to get square footage
Use a fan with a blade span of 29–36 inches for rooms up to 75 sq ft
Use a fan with a blade span of 36–42 inches for rooms 76–144 sq ft
Use a fan with a blade span of 44–50 inches for rooms 144–225 sq ft
Use a fan with a blade span of 50–54 inches for rooms 225–400 sq ft
Use a fan with a blade span of 54 inches or larger for rooms over 400 sq ft
Choose a larger fan for open layouts, high ceilings, or wide spaces
Choose a smaller fan for compact rooms, low ceilings, or narrow spaces
Keep fan blades at least 18 inches from walls
Keep fan blades at least 7 feet above the floor
Keep fan blades at least 8–10 inches below the ceiling
Match fan size to room shape, not just square footage
Use multiple fans for long or irregularly shaped rooms
Check manufacturer recommendations for the specific model