Tool 01 · Calculator

Solar calculator — cost, size and payback

Enter your bill, electric rate and quote price. The calculator estimates annual usage, system size, panel count, gross cost and simple payback — with the post-2025 federal-credit caveat visible.

Inputsbill + rate + $/W

OutputkW, panels, payback

Privacy100% client-side

Panel count calculator Payback calculator

Average monthly electric bill ($) Your electricity rate ($/kWh) Installer quote price ($/W) Panel wattage (W)

System was in service by Dec. 31, 2025, so the 30% federal credit may apply

How this calculator stays honest

Usage: bill ÷ electric rate. If your bill includes fixed charges, this slightly overstates kWh.
Production: 1,200 kWh per installed kW per year — a national rule of thumb. Use the sun look-up for state-specific context.
Federal credit: not assumed by default. The site uses the IRS in-service-by-2025 rule already documented in the federal credit guide.