Solar TOOL
Solar Panel Count Calculator
Estimate a panel count. Use the calculator below with your own numbers.
Solar Panel Count Calculator
Estimate a panel count.
Change the example inputs to your own values. Check the method and limitations below.
How to use this calculator
Enter Target capacity (kW), Panel rating (W). The result updates in your browser as you edit an input. The prefilled values are examples only.
How the estimate works
Convert target kW to watts and divide by panel rating; round up to whole panels.
What can change the answer?
Panel count is a capacity estimate, not a roof layout. Fire setbacks, roof obstructions, structural limits, and inverter selection affect a real design.
Before relying on the result
Check that the figures use the same units and period. Compare the result against a current label, quote, contract, employer policy, or official dataset when appropriate. This estimate does not include factors you have not entered.
Further reference
For source data or a more detailed method, see National Laboratory of the Rockies: PVWatts production model. The calculator does not automatically import data from this source.
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