BTU – Calculator

GUIDEHVAC BTU Calculator — ZIP Code Heating Zone
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
BTU/hr
Approximate AC size

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.