About SunMetricLab
SunMetricLab exists to answer one question honestly: what would rooftop solar actually cost and save for your house? Most online solar estimates are either too vague to act on or built to collect your phone number for installers. This site does neither. The calculators run entirely in your browser, ask for nothing but the numbers on your bill, and show the formula behind every result.
The site has three parts. The calculators size a system, price it, and estimate savings and payback from your own inputs. The state and city cost pages apply the same model to published sun-hour and electricity-rate data, with editorial notes on each state's net metering rules, incentives and utilities. The guides explain the concepts those numbers depend on, from performance ratios to export credits.
Who makes it
SunMetricLab Editorial Team
Independent solar research and calculators
The SunMetricLab editorial team builds the calculators and data models on this site and writes and reviews the guides. The site started as a personal project to size a rooftop system when most online estimates were either vague or tied to a sales funnel. Every figure on the site is modeled from public data and can be reproduced with the formulas on the methodology page.
How the numbers are produced
Every figure on the site is computed from documented formulas and public data: NREL solar resource data for sun hours, U.S. Energy Information Administration averages for electricity rates, IRS guidance for the federal credit, and DSIRE plus state utility commission filings for net metering and incentive rules. The full set of formulas, constants and limitations is on the methodology page, and every data page shows when its inputs were last reviewed.
Guides are planned from a topic map, drafted, checked against the modeling assumptions, passed through automated checks for unsupported claims and template phrasing, and reviewed by the editor before they go live. When a program rule changes or a reader reports an error, the article is corrected and its updated date is set.
Independence and funding
SunMetricLab does not sell leads, does not take payment from installers for placement, and does not rank or recommend specific companies. The site is supported by display advertising, which never influences the formulas or the editorial notes. Calculator results are not stored or sent anywhere.
Estimates are planning tools, not quotes. Real costs depend on your roof, your utility's export terms, local permitting and the installers competing for your job. Get several written quotes and compare them on price per watt.
Contact
Corrections, data questions and partnership requests go through the contact page. If you run a site and want to use a calculator, every calculator page has a free embed snippet with attribution.