How this site figures clothes washers

DOE's test procedure for washers (10 CFR 430, Subpart B, Appendix J2, in force as of 2025-03-21) rates a model by its IMEF: its drum capacity divided by the energy one cycle takes — the machine, heating the water electrically, and the energy an electric dryer needs to remove the moisture the spin leaves (0.5 kWh per pound of water, applied to 91% of loads).

yearly kWh = 295 cycles × capacity (ft³) ÷ IMEF

295 is DOE's own representative number of cycles a year (Appendix J2 §4.4). Because IMEF includes the dryer, this total is right for a home with an electric water heater and an electric dryer, and it is labelled that way wherever it appears. For a home with a gas water heater, a gas dryer or line drying, the total is lower; DOE's database does not file the split, so no such figure is shown.

ENERGY STAR files a yearly kWh for the machine and its electrically heated water without the dryer. It is shown only when ENERGY STAR's own IMEF and capacity for that model match the rating the page shows — a model number alone is not enough, because DOE files some individual numbers under more than one basic model. Today that holds for 365 of 1,279 models; the rest say why the figure is missing.

yearly gallons = 295 cycles × capacity (ft³) × IWF

IWF is the gallons per cycle for each cubic foot of drum (Appendix J2 §4.2.12), so this is every model's own water use at DOE's test. Checked against the gallons ENERGY STAR files for the models it certifies, the two agree to within about one percent. No dollar figure is shown: water and sewer rates are set by thousands of local utilities and no free national source publishes them.

Models are compared only inside DOE's product class — top or front loading, standard (1.6 ft³ or more) or compact — and by IMEF, not by yearly kWh: DOE counts the same cycles for every drum, so a bigger washer always shows more kWh even when it is more efficient per cubic foot. Where a model files exactly its class's federal minimum, the page says so instead of ranking it inside that tie. The minimums (10 CFR 430.32(g)(1), as of 2025-05-20):

The same rule orders the ranked list: IMEF, highest first, inside one class, only above the minimum, and only where at least eight models spread by 8% or more. A model named in a CPSC recall is left out of it, and its own page shows the recall.

A new standard in different metrics (EER and WER, under Appendix J) is due from March 1, 2028. The two never convert, so no figure here mixes them. In May 2025 DOE proposed withdrawing that standard's water limits and the compact-washer standards altogether (Federal Register 2025-08578 and 2025-08581); neither was final when this page was built.

A row in DOE's database is a pair of a basic model and one individual model number it covers; a page is one basic model. When a basic model's rows file different ratings (32 today), the page shows the least efficient one, whole, from a single row, and says the registry lists more than one. The EnergyGuide label is linked only when the registry points at a PDF that three models or fewer share (139 today) — a brand's general manuals page is not this model's label.

The installed-cost range comes from the National Residential Efficiency Measures Database (NLR REMDB), a regression on two inputs: the drum's volume and the washer's own yearly energy use. DOE's database gives the first; only ENERGY STAR gives the second, so a range appears only where the page already shows ENERGY STAR's machine figure (352 models today), and never where a model's inputs lie outside the range the regression was fitted on. It is a modeled range, not a quote, and it does not enter the running cost.

REMDB's figures are in 2023 dollars. The equipment part is brought forward with the Bureau of Labor Statistics producer price index for major household appliance manufacturing — BLS has published no washer-specific index since 2016 — and the installation part with its employment cost index for construction labor.

Your yearly cost is the yearly kWh times the price per kWh on the tariff your utility files for your ZIP, or your state's average residential rate when no tariff could be selected. The page does this in your browser once you enter a ZIP; standing charges are not included because they are not attributable to one appliance.

Sources: DOE CCD, ENERGY STAR, OpenEI URDB.