Free Heating & Cooling Calculator

Heating & Cooling BTU Calculator

Estimate the BTUs needed to heat or cool a room, living space or home using square footage, ceiling height, Texas climate, insulation, windows and sun exposure.

Calculate Required BTUs

BTU Sizing Calculator

Estimate heating and cooling capacity.

If you need a broader whole-system estimate, compare this result with our HVAC size calculator . Final equipment sizing for an HVAC installation should use the actual property load.

Calculate Heating & Cooling BTUs

Enter the space characteristics to generate a preliminary BTU range.

Conditioned Area Enter square feet.

Space Type

Ceiling Height

Texas Climate Region

Insulation

Window Exposure

Sun Exposure

Typical Occupancy / Internal Load

Preliminary BTU Capacity Range - -

This is an informational capacity estimate rather than a final equipment-selection calculation. Actual heating and cooling loads depend on detailed building and climate conditions.

- Approx. Midpoint

Area -

Space -

Climate -

Insulation -

Planning HVAC equipment?

Request HVAC help below after reviewing your preliminary BTU estimate.

BTU calculator note: this tool is intended for early-stage research. Final heating and cooling equipment should not be selected from square footage or an online BTU estimate alone. Detailed load calculations can account for orientation, construction, infiltration, humidity, duct conditions and design temperatures.