BTU Calculator
Estimate BTU for heating or cooling any room in your home.
ft²
BTU needed
9,000
Per hour
Tons of cooling
0.75
12,000 BTU = 1 ton
Room size
300 ft²
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How the btu calculator works
Estimated BTU = room area × climate factor × insulation factor. Climate factor: 20–25 BTU/ft² for mild climates, 30 for average, 40+ for hot or cold zones. Insulation multiplier: 0.9 (well-insulated), 1.0 (average), 1.15 (poor).
Frequently asked questions
How many BTU do I need to cool a 300 sq ft room?
About 7,000–9,000 BTU for an average-insulated room in a moderate climate.
How many BTU in a ton of AC?
12,000 BTU per hour equals 1 ton of cooling capacity.
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