Solar Cost & Payback Calculator
Estimate the cost and payback of rooftop solar. Choose your state and enter your monthly electricity use to see the system size, the installed price, yearly savings and payback period.
- System size
- 7.3 kW (covers 100% of use)
- Price per watt
- $2.25 (Texas average)
- Savings per year
- $1,701
- Simple payback
- 9.7 years
How this calculator works
The system is sized to cover 100% of your yearly use with your state’s solar production (NREL PVWatts). Cost = system watts × the average installed price per watt in your state from EnergySage (2026), or the U.S. average of $2.60/W where no state figure is available.
Yearly savings = the electricity the system produces × your state’s average residential rate (EIA, March 2026). Simple payback = cost ÷ yearly savings. It assumes full credit for every kWh (net metering) and ignores panel degradation and future rate changes.
The 30% federal residential solar tax credit (Section 25D) ended for systems installed after December 31, 2025, so prices here are shown without it. Check state and utility incentives, which can still shorten the payback.
Example: 865 kWh a month in Texas
- System size: 865 × 12 ÷ 1,421 = 7.3 kW.
- Cost: 7,305 W × $2.25 = $16,436.
- Savings: 10,380 kWh × $0.1639 = $1,701 a year → payback in about 9.7 years.
Tips before you buy
- Compare quotes by price per watt: divide the total price by the system size in watts.
- If your utility pays less for exported power than it charges you, a smaller system or a battery may pay back faster.
- Use the solar panel calculator to see how many panels this system means for your roof.
Common sizes
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Guides
Frequently asked questions
How much do solar panels cost in 2026?
EnergySage reports an average of about $2.60 per watt installed before incentives in 2026, so a typical 7 kW system costs around $18,000 and a 12 kW system about $31,000.
Is there still a federal tax credit for solar?
Not for homeowners who buy their system: the 30% residential clean energy credit ended for systems installed after December 31, 2025. Leased systems and PPAs may still benefit indirectly through the installer’s business credit.
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Last updated October 26, 2026