Know your solar numbers before you call an installer
Free, accurate solar calculators and an up-to-date incentive database for US homeowners. Real production estimates from NREL PVWatts® — no email required.
Updated for 2026: the 30% federal solar tax credit for homeowners ended on Dec 31, 2025. Unlike most calculators, Wattcrunch uses the current rules — so your numbers are honest. See what changed →
System Size Calculator
Turn your annual kWh usage into the right solar system size in kW.
Open tool →Solar Savings Calculator
25-year savings, payback, ROI, and NPV with up-to-date 2026 tax rules.
Open tool →Incentive Finder
Search federal, state, and utility solar incentives by state.
Open tool →Advertisement
Advertisement