What is Wattcrunch Solar Calculator?

Wattcrunch Solar Calculator is a free online tool that estimates solar panel system size, costs, savings, payback period, and incentives for US homeowners. It uses real data from NREL PVWatts and current 2026 rules to provide accurate, transparent calculations without requiring user accounts or emails.

Who is it for?

This tool is designed for homeowners considering solar installations, as well as contractors and installers who want to verify or compare project estimates. It benefits individuals seeking reliable financial and production estimates to make informed solar decisions.

How is it priced?

Wattcrunch is completely free to use. No account or email is required. The site is supported by advertising, and users are encouraged to support environmental efforts through optional donations or tree planting programs.

How does it compare to alternatives?

This calculator focuses on providing accurate, up-to-date estimates based on current US federal, state, and utility incentives, as well as real solar production data. It emphasizes transparency of assumptions and detailed comparison of quotes, making it suitable for homeowners and professionals seeking precise financial analysis and system sizing. Users should compare features, data sources, and the ability to verify utility rules when evaluating alternatives.

Key features

Uses NREL PVWatts data for address-based solar production estimates
Calculates optimal system size based on household energy use
Provides 2026-specific financial incentives and tax credits
Allows importing bills via PDF, CSV, or text for accuracy
Enables comparison of multiple installer quotes
Generates homeowner-ready reports for decision-making

Use cases

A homeowner inputs their annual electricity usage and utility rates to determine the appropriate solar system size and expected savings. A contractor uses the tool to verify quote details and compare financing options. An energy consultant assesses local incentives and utility policies to advise clients on solar investments.