Field Tool

Manual J Load Calculator

Estimate heating and cooling loads for residential and light commercial spaces. Get BTU requirements and recommended system sizing in the field.

Estimation tool only. Not a certified Manual J calculation. Always verify with a licensed engineer for permit and equipment specifications.

Building Information

Simple
Location & Climate
Space Details
sq ft
ft
Construction Quality
%

Project Settings

Advanced

Room-by-Room Inputs

Load Results

Fill in the inputs and click
Calculate Load to see results.

Cooling Load (BTU/hr) --
Heating Load (BTU/hr) --
Recommended System Size --
Conditioned Area --
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