Estimate how many solar panels you need based on your daily energy use, monthly energy use, electric bill, panel wattage, peak sun hours, system losses, and solar offset goal. This calculator also estimates solar system size, roof space, monthly production, annual production, savings, cost, and payback period.
Daily kWh mode:
The calculator uses daily energy use, solar offset goal, sun hours, system losses, and panel wattage to estimate how many solar panels you need.
Monthly kWh mode:
The calculator converts monthly kWh into daily kWh, then calculates the solar system size and panel count.
Electric bill mode:
The calculator estimates monthly kWh by dividing your monthly electric bill by your electric rate, then estimates panels needed.
Target production mode:
Enter a target monthly solar production amount to estimate the number of panels required to produce that energy.
A solar panel count calculator helps estimate how many panels may be needed before planning a home solar system, RV solar setup, off-grid system, cabin system, or shed power system.
It can help compare panel count, solar system size, panel wattage, roof space, production, electric savings, system cost, net cost, and payback period.
Your result shows the estimated number of solar panels needed, rounded up to the next whole panel. It also shows the estimated solar system size, total watts, daily production, monthly production, annual production, roof space needed, installed cost, incentive value, net cost, monthly savings, annual savings, and payback period.
Estimate your daily energy use, divide by peak sun hours and system efficiency, then divide the required system watts by the wattage of each solar panel.
Using 900 kWh per month, 4.5 peak sun hours, 20% system losses, and 400-watt panels, the estimate is about 21 solar panels.
Yes. For the same energy target, higher wattage panels usually reduce the total number of panels needed.
You cannot install a fraction of a solar panel, so the calculator rounds up to the next whole panel.
No. This is an estimate. Actual panel count can vary based on roof space, roof direction, shade, panel model, inverter design, local weather, utility rules, and installer recommendations.