Solar Panel ROI Calculator
Last updated July 2, 2026
Solar panels have crossed the threshold from environmental statement to mainstream financial investment in most of the United States, and for homeowners in high-electricity-cost states the return is genuinely compelling. The average cost of a residential solar installation in 2026 runs approximately $2.50 to $3.50 per watt before incentives — meaning a 7-kilowatt system costs $17,500 to $24,500 before the federal Residential Clean Energy Credit, which provides a 30 percent tax credit through 2032. After applying the credit, the net cost drops to roughly $12,000 to $17,000 for a system sized to cover most of a typical household's electricity usage. Most homeowners see a payback period of 7 to 10 years when professional installation is used, and 5 to 7 years for DIY or partial-DIY installations.
The return calculation depends heavily on your local electricity rate and the state of net metering in your area. In California, Massachusetts, and Hawaii — where retail electricity rates exceed 25 to 30 cents per kilowatt-hour — the annual savings on a 7kW system can exceed $2,500, producing payback periods under 7 years and an internal rate of return that compares favorably to stock market returns over the same period. In states with lower electricity rates and less favorable net metering, payback periods extend to 12 to 15 years, reducing but not eliminating the financial case. Solar also adds to home value: Zillow research has estimated that solar installations increase home resale value by approximately 4 percent nationally, though this figure varies by market and buyer demographics.
The solar ROI calculation starts with your current monthly electric bill and your local electricity rate, not the national average. Divide your net system cost (after the 30% tax credit and any state rebates) by your projected annual savings to estimate payback years. If the payback is under 10 years and you plan to stay in the home longer than that, the investment is likely sound on purely financial terms.