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Roof area and coverage
Turns the panel count into a footprint and a percentage of your usage.
The Formula
roof area = panels x panel area, coverage = annual output / annual usage
Turns the panel count into a footprint and a percentage of your usage.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| A | Roof area | square feet | The footprint the array occupies. |
| a | Panel area | square feet | The area of one panel. |
| C | Coverage | decimal | Annual production as a share of annual usage. |
What Each Symbol Means
Asquare feet
Roof area
The footprint the array occupies.
asquare feet
Panel area
The area of one panel.
Cdecimal
Coverage
Annual production as a share of annual usage.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate solar panels needed page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Solar Panels Needed, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.