Solar Array Area Calculator
Estimate solar-panel count, DC array size, module area, spacing footprint, required usable roof area and panel cost.
Default project preview
20 panels
Module surface area
418.4 ft²
Layout footprint
451.9 ft²
Gross roof area needed
602.5 ft²
Area per panel
20.92 ft²
Calculator
Build the material order
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Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Panels = round up (target kW × 1000 ÷ panel watts). Module area = panels × panel length × panel width. Layout spacing and usable-roof fraction expand the required footprint.
FAQ
Solar Array Area Calculator questions
Why is gross roof area larger than panel area?+
Spacing, setbacks, obstructions, access paths and roof geometry prevent full surface coverage.
Does roof orientation affect the geometric area?+
Orientation affects production and layout, while the basic panel rectangle area remains the same.
Can this confirm a roof can support solar panels?+
No. Structural capacity, attachment, wind and roof condition require professional evaluation.