How every number on this site is calculated

The formula

annual cost ($) = certified annual kWh × state rate (¢/kWh) ÷ 100

Monthly cost divides that by 12; daily cost by 365. That's the entire model — no weighting, no adjustments, no proprietary scoring. If you multiply the two public numbers yourself, you'll get our figure.

The two data sources

1 · EPA ENERGY STAR certified products (per-model energy use)

The EPA publishes the full list of ENERGY STAR certified models per product category at data.energystar.gov, including each model's annual energy consumption measured under the relevant DOE test procedure. Our current snapshot was certified through July 2026. These are standardized laboratory figures — the same ones behind the yellow EnergyGuide labels.

2 · US EIA state electricity rates

The U.S. Energy Information Administration publishes the average residential price of electricity by state in its Electric Power Monthly (Table 5.6.A). We use the April 2026 figures; the U.S. average is currently 18.8¢/kWh.

What the certified kWh figures assume

Each category's annual-kWh figure bakes in a standardized usage pattern from the DOE test procedure. Costs are only as "typical" as these assumptions:

Refrigerators: The certified annual kWh comes from the DOE test procedure, which measures continuous 24/7 operation at standardized temperatures — refrigerators never get a day off.
Freezers: The certified annual kWh comes from the DOE test procedure, which measures continuous 24/7 operation at standardized temperatures.
Dishwashers: The certified annual kWh assumes 215 wash cycles per year (the DOE standard, roughly 4 loads a week) and includes the energy to heat water.
Clothes Washers: The certified annual kWh assumes 234 wash cycles per year (the DOE standard, about 4–5 loads a week) and includes water-heating energy.
Clothes Dryers: The certified annual kWh assumes 283 drying cycles per year under the DOE test procedure. Only electric dryers are listed here — a gas dryer's running cost is mostly gas, not electricity.
Room Air Conditioners: The certified annual kWh assumes 750 cooling hours per year (the DOE standard). In hot climates real usage can run well above that; in mild ones, below.
Televisions: The certified annual kWh is based on the standardized ENERGY STAR duty cycle of about 5 hours of on-time per day plus standby the rest of the time. Heavy streaming households will use more.
Computer Monitors: The certified annual kWh (TEC) assumes the monitor is on 35% of the day and asleep the other 65%, per the ENERGY STAR test basis.
Air Purifiers: The certified annual kWh comes from the ENERGY STAR room air cleaner test basis, which assumes continuous daily operation. Running fewer hours costs proportionally less.
Dehumidifiers: The certified annual kWh comes from the DOE test basis for standardized annual runtime. Damp basements that run a unit year-round will exceed it; seasonal use will come in under.
Water Heaters (Electric): The certified annual kWh comes from the DOE Uniform Energy Factor test, which simulates a typical household's daily hot-water draw pattern. Only electric models (including heat-pump units) are listed — gas models burn gas, not kWh.

How the data is cleaned

Models missing the energy field for their category are dropped entirely — we never estimate a certified figure.
Retailer SKUs and finish variants that share a brand, normalized model number, and identical energy figures are clustered into one canonical model; the variant SKUs are listed on its page.
Gas clothes dryers and gas/propane water heaters are excluded — their running cost is mostly fuel, not electricity, so a kWh figure would mislead.
Signage displays are excluded from computer monitors (no annual-kWh figure is reported for them); models not marketed in the United States are excluded everywhere.
Categories ENERGY STAR certifies for something other than annual kWh (ceiling fans, pool pumps) get transparent wattage calculators instead of model cost pages.

Limitations — read this part

Test conditions aren't your house. Real usage (thermostat settings, load sizes, climate, hours of use) can move actual consumption well above or below the certified figure.
State averages hide variation. Your utility's rate, tiered pricing, fixed charges, and time-of-use plans mean your marginal ¢/kWh may differ substantially from the state average.
Certified models only. ENERGY STAR covers efficient models; the market's worst performers aren't in this data, so "power-hungry" here means power-hungry among certified models.
These are comparison estimates, not bill predictions. Use them to choose between appliances, not to forecast a utility bill.

Refresh cadence

ENERGY STAR data is re-pulled and rates are updated monthly (EIA publishes with a roughly two-month lag). Current snapshot: ENERGY STAR 2026-07-02, EIA period 2026-04, site data built 2026-07-02.