How many panels do you need? What will it cost — including inverter and battery? What's your payback period? Find out in 60 seconds.
Based on 2026 US solar costs, state electricity rates, and real peak sun hour data
The number of solar panels you need depends on three things: how much electricity you use, how much sun your location gets, and how large the panels are. Our calculator handles all of this automatically.
We convert your monthly bill to kWh using your state's 2026 electricity rate. The US average is 903 kWh/month at 18.05¢/kWh ($163/month). Your state's rate may be higher or lower.
Arizona and Nevada get 6.5 peak sun hours per day — meaning panels produce far more power than in Washington (3.5 hrs). Fewer sun hours = more panels needed for the same output.
Most modern solar panels are rated at 430W. We divide your system size (in watts) by the panel wattage to get the minimum number of panels — always rounding up to the next full panel.
Every solar system needs an inverter to convert DC power from panels to AC power for your home. Grid-tied inverters cost $1,200–$2,500 for typical home systems. Batteries are optional — they store excess solar energy for nighttime use or outages, and cost $9,000–$18,000 per unit installed.
Not sure of your kWh usage? Start here to understand your current bill first.
Estimate Bill →Explore wind, biogas, and micro-hydro as complements or alternatives to solar.
Explore Alternatives →Detailed 2026 solar pricing for every US state — with tips on getting the best deal.
Read Guide →