Measure the room length and width
Multiply length by width to get square footage
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 inches or larger, or use multiple fans
Choose a larger fan for high ceilings or open spaces
Choose a smaller fan for low ceilings or compact rooms
Match fan size to room shape and airflow needs
Check manufacturer size recommendations before buying