Manual J Load Calculator

Home Square Footage (sq ft):

Number of Rooms:

Number of Windows:

Insulation Level (1-5):

Climate Zone Factor for Heating (BTU/sq ft):

Climate Zone Factor for Cooling (BTU/sq ft):

Click here: What is Home Square Footage?

The total floor area of your home in square feet. Larger homes require more heating and cooling capacity.

Click here: What is the Number of Rooms?

The total number of rooms in your home. Each room adds to the heating and cooling demand due to air circulation needs.

Click here: What is the Number of Windows?

Windows influence heat gain and loss. More windows typically mean higher heating and cooling requirements.

Click here: What is Insulation Level?

A rating of your home's insulation quality. A value of 1 means poor insulation, and 5 means excellent insulation.

Click here: What are Climate Zone Factors?

Climate Zone Factors are BTU requirements per square foot based on your region's climate. Heating zones range from 20-50 BTU/sq ft, and cooling zones range from 15-35 BTU/sq ft.

Manual J Load Calculator

Manual J Load Calculator

Search Here