
GUIDEHVAC • HVAC TOOLS
BTU Calculator
Estimate heating or cooling requirements using your room details and ZIP-code heating region.
Enter a ZIP code to identify the location.
You can override the suggested region if you know your local heating zone.
Estimated cooling load
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BTU/hr
Approximate AC size
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—
How the estimate was calculated
- Location—
- Room area—
- Base / zone load—
- Ceiling adjustment—
- Climate adjustment—
- Insulation adjustment—
- Sun exposure—
- Windows—
- People—
- Building location—
- Appliances—
Important: This is a preliminary sizing estimate, not a Manual J load calculation. Final equipment sizing should account for local design temperatures, envelope construction, infiltration, windows, ducts, orientation and other building-specific factors.