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Solar

Solar System Size Calculator

Start with monthly consumption, then adjust the local peak-sun-hours and system performance assumptions.

Formula shown Browser-only inputs Offline ready
Your inputs

Enter your household details

Your numbers stay in this browser. Nothing is uploaded.
Your estimate

Indicative solar system size

3.08 kW

A system near 3.08 kW could offset the entered monthly consumption under your sunlight and performance assumptions.

Daily demand12 kWh
Indicative roof area308 sq ft
Annual target4,320 kWh

Keep in mind

This is an energy-balance estimate, not an installation design.

Shading, orientation, inverter sizing and local approvals need a site survey.

How this estimate works

A simple formula, visible assumptions

System kW = daily energy ÷ (sun hours × performance ratio).

The result updates in your browser as you change an input. It is a planning estimate, so compare it with real bills, product specifications and a qualified professional's assessment.

Read the full methodology
A better input gives a better result

Before you calculate

  • Use a recent electricity bill or equipment nameplate.
  • Enter prices and tariffs that apply to your household.
  • Keep notes from installers or manufacturers nearby.
  • Recalculate when your usage pattern changes.
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