Solar Energy Calculators & Tools
Free, data-backed calculators to estimate your solar costs, savings, and tax credits. All calculations use real installation data from millions of US residential solar systems.
Solar Cost & Payback Calculator
4-20 kW systems • All 50 states
Estimate your solar panel system cost, federal ITC savings, annual production, and break-even payback period. Adjust system size and state to get localized estimates based on real installation data from 4.5M+ systems.
Solar Tax Credit Calculator
Federal ITC + State Credits • 2026
Calculate your 30% federal solar Investment Tax Credit (ITC) and applicable state credits. Includes IRS Form 5695 guidance, carry-forward rules, and a state-by-state credit lookup for all ownership types.
About Our Data
All calculations use state-level data from the LBNL Tracking the Sun dataset (Lawrence Berkeley National Laboratory) and the U.S. Energy Information Administration (EIA). System cost estimates reflect real installer pricing from 4.5 million+ residential installations tracked through the Tracking the Sun program. Electricity rates use the most recent EIA residential average by state. Sun hours data is sourced from NREL (National Renewable Energy Laboratory) PVWatts.
Data sources: LBNL Tracking the Sun • U.S. EIA • NREL PVWatts • IRS Publication 946