DIY

What Size Ceiling Fan Do You Need?

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate the right ceiling fan diameter and CFM for any room size. Plus mounting height and downrod length.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

In this article

Fan Size by Room Size
Mounting Height Matters
CFM: The Number That Matters

Guia de Tamanho

Menos de 7 m²: 76-91 cm. 7-13 m²: 91-107 cm. 13-21 m²: 112-132 cm. Mais de 21 m²: 132-142 cm ou dois ventiladores. No Brasil, ventiladores de teto são essenciais — presentes em 60%+ dos lares. Marcas populares: Ventisol, Arno, Spirit. Um ventilador grande em velocidade baixa é mais silencioso que um pequeno em alta.

Economia

Ventilador de teto: R$0,02-0,10/hora. Ar-condicionado: R$0,50-2,00/hora. O ventilador permite elevar o termostato do AC em 3-5°C para mesma sensação = economia de 20-40% na conta de luz. No clima brasileiro, a combinação ventilador + AC é a mais eficiente.

⚡ CalcWolf Insight

Running a ceiling fan costs approximately $0.01-0.02 per hour vs $0.20-0.50/hour for air conditioning. Using a fan to raise your thermostat by 4°F saves roughly $50-100 per cooling season. In winter, reverse the fan direction (clockwise on low) to push warm air down from the ceiling.

Frequently asked questions

Qual tamanho para sala de 16 m²?▾

132 cm. Procure vazão de 4.000+ CFM. No Brasil: Ventisol e Spirit são excelentes custo-benefício.

Economiza mesmo?▾

Sim — permite subir o AC em 3-5°C. Gasta R$3-8/mês vs R$100-300 do AC. Economia real de 20-40%.

✓ Math logic verified against primary sources → See our verification process

Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →