Free Solar Tools
Eight free tools, all built around the same SolarSpec database of 260+ datasheet-verified products and a single-source incentives table. No email gate, no lead-gen funnel, no "we'll connect you with a local installer" hand-off. If you give us five fields, we give you a specific model. If you give us a roof area, we give you a panel count and an annual kWh estimate.
Start with the AI Setup Recommender — it's the fastest path from "I want solar" to a real, named product list. Or pick a specific calculator below.
All tools
Every tool is free, runs entirely in your browser, and never asks for your email.
AI Setup Recommender
5 fields in, a specific panel + inverter + (optional) battery model out. Picks come from our 260+ scored database, with the math shown.
Open tool →Solar Payback Calculator
How fast solar pays for itself given your state, monthly bill, system size, and battery choice. Uses our single-source incentives table (no stale 26% bug).
Open tool →Solar Cost Calculator
Total install cost + annual savings + payback period by state and panel tier. Includes federal ITC and state-level incentives.
Open tool →Roof Size Calculator
Enter your available roof area; we tell you how many panels fit, which models maximise your kWh, and the estimated annual production.
Open tool →Battery Backup Calculator
Pick the appliances you want to keep running during an outage, pick a battery, see how many hours you get before the lights go.
Open tool →Battery Sizing Calculator
Inverse of the backup calculator: tell us your essential loads and desired backup hours, we tell you how many kWh you need and a model that fits.
Open tool →Compare Equipment
Side-by-side spec tables for 600+ panel, inverter, battery, and charge-controller matchups. Same wattage class only. Every figure traced to a datasheet.
Open tool →Patina Self-Audit
How we score the site against the Patina content-quality framework (10 dimensions, image density to citation density). Published openly so you can audit us.
Open tool →
How our tools work
Every calculator on this page reads from the same JSON product database that powers our Best of 2026 rankings and side-by-side comparisons. That database currently holds 260+ verified products across panels, inverters, batteries, and charge controllers. If we can't source a spec from the manufacturer's own datasheet, the field stays empty — we never average across listings or fill in plausible-looking placeholders.
Financial assumptions (federal Investment Tax Credit, state incentives, utility rates) live in a single source-of-truth table so the payback calculator and the state buying guides can never disagree. When a number changes, every page updates at the next build.
We do not accept money from manufacturers, installers, or lead-gen brokers. Read the full methodology and editorial policy for the unabridged version.