solar energyClassic tool
Residential Solar Calculator
Estimate system size, monthly generation, panel count, roof area and potential savings for a home solar setup.
Use this residential solar calculator to turn your monthly energy use into a practical first estimate for a rooftop solar system.
The calculation combines monthly kWh consumption, peak sun hours, target offset, system performance and panel wattage to build a realistic starting point.
You can also estimate how many panels you need, how much roof area to reserve and what monthly savings the informed energy rate can represent.
Use clear inputs to get a more useful result.
How to use a residential solar calculator
A solar system is usually sized from monthly consumption and the average production potential at the property. Instead of guessing panel count, start with the energy you want to offset and the real conditions of the roof.
How to fill the fields
- Use the average kWh consumption shown on recent electricity bills.
- Enter local peak sun hours and a realistic performance ratio to reflect system losses.
- Compare system size, panel count and roof area before requesting quotes.
What are peak sun hours?
It is a practical average of useful solar irradiation available for production during the day. Different regions have different values, so this field strongly affects the estimate.
Should you aim to offset 100% of the bill?
Many homes start near 100%, but the best target depends on future consumption, local regulations and budget. In some cases a partial offset already delivers a strong return.
Does this replace engineering and inspection?
No. It is a pre-sizing tool. Electrical design, roof structure, shading and utility approval still need technical validation before installation.