How do I find my kWh usage?

From your electricity bill, or enter the bill amount and we'll estimate the kWh.

What are peak sun hours?

The daily average of full-irradiance hours. We default to the capital's value.

It's a rough estimate. Installation needs an engineering survey of roof, shading, and orientation.

Peak sun hours genuinely vary between countries and cities.

No, the calculation is entirely local.

Estimate required system size, panel count, and roof area.

Practical calculatorFully localized assumptionsCountry-specificInteractive chart

Last updated: 2026-05-16

Source: default

kW = Daily kWh / (Sun hours × Performance Ratio)

How do I find my kWh usage?: From your electricity bill, or enter the bill amount and we'll estimate the kWh.
What are peak sun hours?: The daily average of full-irradiance hours. We default to the capital's value.
Is the result accurate?: It's a rough estimate. Installation needs an engineering survey of roof, shading, and orientation.
Why do numbers differ by country?: Peak sun hours genuinely vary between countries and cities.
Do you store my data?: No, the calculation is entirely local.

Results are estimates and not professional advice. Verify important decisions with a qualified professional.