How do I calculate ventilation? Enter your numbers above and the result updates instantly. For example: Floor area: 2,200 sq ft · Bedrooms: 3 → Required ventilation (ASHRAE 62.2): 96 CFM.
Is this Ventilation Calculator free? Yes — completely free with no sign-up or paywall. It runs entirely in your browser and keeps working offline; the numbers you enter never leave your device.
How accurate is it? It uses the standard published formula for ventilation. Results are estimates for planning — not financial, tax, medical, engineering, or legal advice.