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Calculator

Solar System Size Calculator

Estimate the solar system capacity you need based on your daily energy consumption, location, and system efficiency assumptions.

Continuously maintained3 min read Focus Solar Editorial Team Reviewed for technical accuracy through the Focus Solar editorial process

Enter your daily kWh consumption and location to calculate the approximate solar array size required to meet your energy needs. This calculator accounts for peak sun hours, system losses, and a safety margin to give you a realistic capacity estimate.

YOUR INPUTS

Estimate system size

Adjust the assumptions. Results update immediately.
kWh/day
Range 1–300
hours/day
Range 1–8
%
Range 0–40
W
Range 250–700
Planning estimate only

How to use this estimate

This result is an early decision aid, not an approved electrical or structural design. Weather, shading, orientation, equipment efficiency, local rules, and actual product specifications can change the outcome.

Regional differences: Costs, taxes, incentives, tariffs, and grid rules vary by location and over time.

Read the calculation methodology →