BTU Calculator
Estimate BTU for heating or cooling any room in your home.
Use this BTU calculator to estimate the heating or cooling capacity needed for any room in your home. The estimate is based on room area, climate, and insulation quality.
BTU needed
9,000
Per hour
Tons of cooling
0.75
12,000 BTU = 1 ton
Room size
300 ft²
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Recommended tools & materials
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Smart Thermostat
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How does the btu calculator work?
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).
What else do people ask about this calculator?
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.
Which related calculators should I use next?
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