Methodology

How we make the numbers useful.

Greener Numbers uses primary public sources wherever possible and labels estimates clearly.

Electricity

We use EIA retail-sales and revenue data for state-level comparisons. Average retail price is a revenue-per-kilowatthour measure and should not be treated as a utility tariff.

Vehicle costs

The EV calculator estimates annual fuel or electricity use from miles, efficiency, and user-entered prices. It intentionally excludes ownership costs that vary widely between drivers.

Corrections

If a source changes or an error is identified, we update the page, record the revision date, and explain a material methodology change in the article or data note.

Primary sources