Methodology

1. Primary data source

All prices come from the U.S. Energy Information Administration's Weekly Retail Gasoline and Diesel Prices survey, series family EMM_EPMR_PTE_*_DPGw. The series reports regular gasoline, all formulations, in dollars per gallon, including all federal, state, and local taxes. The underlying survey samples retail outlets and is published weekly, typically on Monday for the prior week.

We download the official EIA workbook for each series, parse the weekly observations, and store weekly points from 2000 to the present. Our current build uses data through 2026-10-26.

2. What is actually measured

Geography	EIA series	Status on this site
United States	EMM_EPMR_PTE_NUS_DPGw	National average, every page uses it as the benchmark
9 census divisions (PADDs)	EMM_EPMR_PTE_R*.DPGw	Regional benchmark, used for states without a state series
California, Colorado, Florida, Massachusetts, Minnesota, New York, Ohio, Texas, Washington	EMM_EPMR_PTE_S*.DPGw	True weekly state averages
Boston, Chicago, Cleveland, Denver, Houston, Los Angeles, Miami, New York City, San Francisco, Seattle	EMM_EPMR_PTE_Y*.DPGw	Published metro averages

The EIA does not publish a weekly statewide average for the other 41 states. For those states we display the PADD average for the district that contains the state, and label it regional benchmark everywhere it appears. It is never presented as a state-level measurement.

3. State-to-PADD mapping

• PADD 1A — New England: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont
• PADD 1B — Central Atlantic: Delaware, District of Columbia, Maryland, New Jersey, New York, Pennsylvania
• PADD 1C — Lower Atlantic: Florida, Georgia, North Carolina, South Carolina, Virginia, West Virginia
• PADD 2 — Midwest: Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Wisconsin
• PADD 3 — Gulf Coast: Alabama, Arkansas, Louisiana, Mississippi, New Mexico, Texas
• PADD 4 — Rocky Mountain: Colorado, Idaho, Montana, Utah, Wyoming
• PADD 5 — West Coast: Alaska, Arizona, California, Hawaii, Nevada, Oregon, Washington

4. Calculations

Week change: current value minus the observation seven days earlier (or the nearest earlier available observation). Four-week change: current value minus the observation 28 days earlier. Year change: current value minus the observation 364 days earlier. 52-week range: the minimum and maximum of all observations in the trailing 364 days. All prices are stored to three decimals and displayed as dollars per gallon.

Calculator formulas are listed on each tool page. In short: trip cost = (miles ÷ MPG) × price; cost per mile = price ÷ MPG; commute cost = round-trip miles × days × weeks ÷ MPG × price; EV cost = (miles ÷ mi/kWh) × blended electricity price.

5. Update cycle

The data files are refreshed by a scheduled build that checks the EIA workbook release each week. When a new week is available, every page is regenerated with the new values and the date printed on each price panel changes with it. Pages are static, so the site does not query a live API on page load — that is why it loads quickly and why the date on the page is always the date of the data.

6. Known limitations

• Not station-level. Prices are survey averages. A specific station can be 20 to 40 cents above or below the average.
• Not real-time. The weekly series lags daily station prices by up to a week.
• Regional, not state, for 41 states. The benchmark is the best public proxy, not a measurement of that state.
• Regular grade only. Midgrade, premium, and diesel are not shown on price pages, though they are available in the source data.
• No cash-discount pricing. Some stations advertise a lower cash price; the survey reflects the average posted price.

7. Corrections

If a figure on this site does not match the EIA source for the same series and week, email hello@gasprices.cyou with the page URL and the week in question. Verified errors are fixed and the page's updated date is changed.