DATA SOURCES
Where the calculator’s numbers come from
Published averages are a starting point. Your current bill, an EnergyGuide label, or measured appliance use will usually be more specific to your home.
Residential electricity rates
The current snapshot is 2026-05, retrieved 2026-07-29. National and state figures come from the U.S. Energy Information Administration’s monthly residential retail-sales dataset.
EIA calculates average retail revenue per kilowatt-hour as a proxy for retail prices. It is not a utility tariff and does not reproduce fixed charges, taxes, tiered pricing, or time-of-use periods. Use the variable rate from a bill when available.
- EIA electricity retail-sales data browser
- EIA API technical documentation
- EIA explanation of retail prices and consumption
How we check each rate update
An automated monthly check publishes only a period containing the national average, all 50 states, and the District of Columbia. The update is rejected if a value is missing, is not numeric, or falls outside a reasonable range. Approved rates are built into the site. The EIA API key is never sent to a visitor’s browser.
Appliance information
Preset profiles are editable planning examples, not measurements of a particular model. For a purchase comparison, prefer the annual kilowatt-hours on the model’s FTC-required EnergyGuide label. ENERGY STAR certification is useful supporting information, but products should still be compared within an equivalent size and configuration.