Solar Cost Calculator
Estimate the rough installed cost of a home solar system using system size and a customizable price-per-watt assumption. Use the result as a planning estimate, not a quote.
Basic formula: system size in watts × price per watt. Real-world quotes can differ because of roof complexity, equipment, labor, permitting, financing, local market conditions, and other soft costs.
How the solar cost estimate works
The calculator multiplies your system size by the assumed installed price per watt. For example, an 8 kW system at $3.00/W produces a gross estimate of $24,000 before any incentives or discounts you enter.
What changes the price of solar?
- System size: Larger systems generally cost more in total, even though price per watt can vary.
- Roof and site conditions: Roof pitch, layout, shading, electrical work and other site conditions can change installation costs.
- Equipment: Panels, inverters, racking and optional batteries affect the project price.
- Soft costs: Permitting, design, labor, sales and project administration can make up a meaningful part of a residential solar quote.
- Location: Local labor markets, utility requirements and incentives can produce large state-to-state differences.
- Financing: A loan can change the total amount paid even when the advertised project price looks similar.
Use this calculator with a real solar quote
For a better estimate, compare the calculator result with at least two or three written proposals. Look at the system size, equipment, estimated annual production, cash price, financing terms and any assumptions about incentives. A low price per watt is not automatically the best deal if the system is smaller or the production estimate is weaker.
Important note about incentives
Incentive programs can change and eligibility depends on the project, location and timing. Do not treat the incentive field in this calculator as a current tax-credit calculation. Verify any federal, state, local or utility incentive before using it in a purchase decision.