Calculators, System Sizing

Manual J Load Calculator

Estimate heating and cooling loads for residential and light commercial spaces. Simple whole-home mode or advanced room-by-room breakdown. Get BTU requirements and recommended system size in tons.

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

Building Information Simple

Location & Climate

Climate Zone

Space Details

Conditioned Area

sq ft

Ceiling Height

Number of Floors

Number of Occupants

Construction Quality

Wall Insulation

Ceiling / Attic Insulation

Window Type

Window Area (% of floor)

Air Sealing

Duct Location

Load Results

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

Cooling Load

Heating Load

Recommended System Size

Conditioned Area

Labor Rate Calculator

Set your rate before you price the job

→

Job Profitability Calculator

Know if the job actually made money

→