Ever wonder what size a solar panel system you need or how much one costs? Use our solar power calculator to estimate the cost and size of a solar energy project in your area. This should only be used as a rough estimate, and may not include any federal, state, or local solar incentives / rebates. A solar installer would be able to provide you with a more accurate estimate. Our calculator also gives rough estimates on how much carbon emissions your current electricity usage contributes to our Earth's global warming. Are you doing your part in helping save our planet?