Get the right AC size for any home. Enter the room details and get an accurate BTU recommendation with climate zone and insulation adjustments.
This free BTU calculator for room size helps HVAC contractors and homeowners find the right AC or heating tonnage for any space. Enter square footage, ceiling height, climate zone, and insulation — get an accurate BTU and tonnage recommendation instantly. No sign-up required.
⚠️ This calculator provides a simplified estimate. A full Manual J load calculation is recommended for precise sizing, especially in older homes or unusual configurations.
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