Home & Construction
Solar Panel Calculator
Calculate solar panel needs and savings
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Frequently asked questions
What does the Solar Panel Calculator do?
It helps you calculate solar panel needs and savings.
What inputs do I need?
Enter Monthly usage, Sun hours per day, and Panel wattage.
Are decimals supported?
Yes, you can use decimal values where appropriate.
Related tools
About this tool
Inputs
- Monthly usage
- Sun hours per day
- Panel wattage
Results
- System size
- Panels needed
You do not need a spreadsheet to calculate solar panel needs and savings. This Solar Panel Calculator gives you the answer in seconds. All you need to supply is monthly usage, sun hours per day and panel wattage. From there, the tool determines system size and panels needed. Having a dedicated tool to calculate solar panel needs and savings saves time you would otherwise spend searching for formulas or setting up a spreadsheet.
Factor in door and window openings, which reduce the material needed for walls. Knowing the math behind a project helps you evaluate contractor quotes and catch mistakes. Flooring area = room length × room width, plus a waste factor (usually 10% for straight lay, 15% for diagonal). Material waste factors (typically 5-15%) should be added on top of the theoretical amount. Run the calculation with your best-case and worst-case assumptions to bracket the likely outcome.