According to our latest annual Refinery Capacity Report, U.S. operable atmospheric distillation capacity, the primary measure of refinery capacity, totaled 18.4 million barrels per calendar day (b/cd) on January 1, 2025—essentially flat compared with last year.

We publish two measures of refinery capacity in the report: barrels per calendar day and barrels per stream day. Calendar day capacity represents the operator’s estimate of the input volume that a distillation unit can process in a 24-hour period under usual operating conditions, factoring in both scheduled and unscheduled maintenance. The calendar day capacity reported by companies may differ slightly from other published figures because of differences in estimation methods.

Stream day capacity reflects the maximum input that a distillation facility can process within a 24-hour period when running at full capacity with an optimal crude oil and product slate and with no allowance for downtime. Stream day capacity is typically about 6% higher than calendar day capacity.

In 2025, the three largest refiners in the United States—Marathon, Valero, and ExxonMobil—all reported calendar day capacity increases of less than 1% compared with 2024. These changes likely stem from small-scale process improvements, rather than major capacity expansions, unlike previous years. No major refinery expansions or transactions occurred from January 2024 through January 2025, unlike in 2023 when a handful of major projects were completed, including a significant expansion at ExxonMobil’s Beaumont, Texas, facility.

Motiva’s Port Arthur refinery reported increased calendar day throughput, regaining its position as the largest single U.S. refinery on a barrels-per-calendar-day basis. However, the facility’s stream day capacity remained unchanged compared with 2024. On a barrels-per-stream-day basis, Marathon’s Galveston Bay refinery remains the largest in the United States, at 665,000 barrels per stream day.

LyondellBasell ended refining operations at its 263,776-b/cd refinery in Houston in March 2025, but the report does not reflect this change because the facility was still operational on January 1.

This year’s Refinery Capacity Report includes 132 operable refineries, the same as in 2024. The count does not include the Philipps 66 Rodeo refinery, which converted to renewable diesel production last year and has potential to produce sustainable aviation fuel as well.

Our report also added Pasadena Performance Products, a new facility near Houston, Texas. Owned by Next Wave Energy Partners, the facility exclusively produces alkylate, a valuable blending component for motor gasoline. The facility uses natural gas liquids to produce alkylate instead of refining crude oil and hasn’t reported traditional refinery units such as a crude oil distillation column.

The 2025 Refinery Capacity Report captures U.S. refining capacity changes in effect as of January 1, 2025.

Source: EIA