basic

Solar Panel Calculator

System size for a target monthly energy production.

Estimate the solar panel system size needed to cover your monthly electricity usage given local sun hours and system efficiency.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

kWh
%
W

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

System kW ≈ (monthly kWh / 30 / sun hours) / system efficiency.

In depth

Estimate the solar panel system size needed to cover your monthly electricity usage given local sun hours and system efficiency.