Ceiling Fan Size Calculator

Get the right ceiling fan blade span and airflow (CFM) for a room from its floor area.

Inputs
sq ft
Results update as you type — no submit
ResultsLIVE
Recommended fan size
44–50 in span
≈ 112–127 cm
Airflow class4,000–5,000 CFM · 6,796–8,495 m³/h
Room typeLiving or dining room
Match the downrod length to your ceiling height so the blades hang about 8–9 ft off the floor for the best breeze.
Formula
200 sq ft → Living or dining room: 44–50 in span
How it works

Ceiling fans are sized by blade span — the diameter the blades sweep — and the fan industry matches that span to the room's floor area. A fan that is too small barely stirs the air; one that is too big for the room looks overwhelming and can feel gusty. The American Lighting Association and ENERGY STAR publish the same buckets, and this calculator reads your span straight off them.

Small rooms up to `75` square feet, like a bathroom or breakfast nook, take a `29`–`36` inch fan. Bedrooms and offices from `76` to `144` square feet want `36`–`44` inches. Living and dining rooms up to `225` square feet take `44`–`50` inches, and great rooms up to `400` square feet take `50`–`54` inches. Above `400` square feet you move to a `54`–`72` inch fan or, better, two fans spread across the space.

Airflow is the second half of the story. It is measured in CFM — cubic feet of air moved per minute on high — and rises with blade span, from roughly `1,000`–`3,000` CFM for a small fan to `6,000`–`7,000` for a great-room model. More CFM is not automatically better; an efficient fan moves more air per watt. When you buy, also match the downrod length to your ceiling height so the blades sit about `8`–`9` feet off the floor for the best breeze.

Worked example
Room `200` sq ft (living room)
area bucket `145`–`225` sq ft → blade span `44`–`50 in` (`112`–`127 cm`)
typical airflow `4,000`–`5,000 CFM`
Questions about ceiling fan size
Match blade span to floor area: up to 75 sq ft take 29–36 in, up to 144 sq ft take 36–44 in, up to 225 sq ft take 44–50 in, up to 400 sq ft take 50–54 in, and larger rooms take 54–72 in or two fans. A typical 12 × 15 ft bedroom (180 sq ft) fits a 44–50 in fan.
SOURCES — American Lighting Association / ENERGY STAR fan-sizing guidance · retailer span charts
Rule-of-thumb estimate — a Manual J load calculation by a licensed HVAC pro is definitive
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