Solar Panel Calculator
Estimate solar array size and panel count from daily electricity use and peak sun hours.
How to Use the Solar Panel Calculator
Enter electricity usage, expected solar production and system assumptions to estimate the solar capacity required.
Practical Example
If a home uses 900 kWh per month and the assumed system output supports about 120 kWh per installed kW each month, roughly 7.5 kW of solar capacity would be needed before losses.
Factors That Affect the Result
Sunlight hours, roof orientation, shading, panel efficiency, inverter losses, weather and local utility rules can change real system performance.
Frequently Asked Questions
Is the estimate a final system design?
No.
Does shading matter?
Yes.
Should installer estimates be compared?
Yes, especially for site-specific design.
Solar System Size and Energy Use
Basic sizing compares daily electricity demand with expected solar production. Peak-sun hours, panel orientation, shading, temperature, inverter losses and seasonal weather all affect output. A nameplate system size does not guarantee the same energy production every day.