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Both calculators run independently — change the inputs on either side to compare results.

Solar Load Calculator

Calculate the total daily energy demand of your home's lighting, appliances, and HVAC to correctly size a solar system. Use this before getting solar quotes to know exactly how many kilowatt-hours per day you need to generate.

Lighting Load (watts)

Appliances Load (watts)

HVAC Load (watts)

Average Daily Usage (hours)

System Efficiency Factor

Fill in the required fields to see your result.

Solar Energy

Solar Roof Area Calculator

Determine how many solar panels fit on your roof by entering its dimensions, pitch angle, and usable area percentage. Ideal for homeowners and installers planning a new solar installation.

Roof Length (feet)

Roof Width (feet)

Roof Pitch

Usable Roof Area

Panel Size (sq ft)

Fill in the required fields to see your result.

Key differences

	Solar Load Calculator	Solar Roof Area Calculator
Category	Solar Energy	Solar Energy
Inputs required	5	5
Result	Required Solar Capacity (kW)	Maximum Panels That Fit (panels)
What it does	Calculate the total daily energy demand of your home's lighting, appliances, and HVAC to correctly size a solar system. Use this before getting solar quotes to know exactly how many kilowatt-hours per day you need to generate.	Determine how many solar panels fit on your roof by entering its dimensions, pitch angle, and usable area percentage. Ideal for homeowners and installers planning a new solar installation.