☀️ Solar Panel Calculator
Estimate how much energy your solar panel system will produce and how much it could save you each year.
What this calculator does
This tool estimates how much electricity a rooftop or ground-mounted solar panel system will generate, based on your panel count, panel wattage, local sunlight, and system performance, along with the resulting bill savings and avoided emissions.
How the estimate is calculated
System size in kilowatts is found by multiplying the number of panels by each panel’s rated wattage. Daily energy output multiplies that system size by your location’s average peak sun hours (the equivalent hours of full-intensity sunlight per day) and a performance ratio, which accounts for real-world losses from inverter efficiency, wiring, heat, dust, and shading — typically 0.75 to 0.85 for a well-installed system. Multiplying the daily output by 365 gives an annual estimate, which is then multiplied by your local electricity rate for savings, and by an average grid emissions factor of about 0.42 kg CO2 per kWh to estimate avoided emissions.
Actual output varies with weather, panel orientation, tilt, temperature, and shading, so use this as a general planning estimate rather than a guaranteed production figure — a solar installer’s site-specific assessment will be more accurate.