Free OnlineCalculators & Converters
HVAC BTU Calculator
Calculate BTU heating or cooling capacity needed for any room. Accounts for insulation, climate zone, occupants, and windows.
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Key Features — HVAC BTU Calculator
BTU/hr from room dimensions
Insulation quality factor
Climate zone adjustment
Occupant and window heat load
Recommended AC size in tons
Why Use This Tool — HVAC BTU Calculator
Free Online Hvac calculatorBtu calculator — for EveryoneFast & Easy Air conditioner size calculatorHow many btu do i need — 100% FreeFree Online Room ac calculatorCooling capacity calculator — for Everyone
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Frequently Asked Questions — HVAC BTU Calculator
How many BTUs per square foot?
20–25 BTUs/sq ft for moderate climate. Add 10% for poor insulation; subtract 10% for well-insulated homes.
What does "tons of cooling" mean?
1 ton = 12,000 BTU/hr. Common sizes: 1.5–5 tons. Oversized units short-cycle and reduce humidity control.
Oversized vs undersized AC?
Too large: short cycles, poor humidity, temperature swings. Too small: runs constantly, fails to cool on hot days.