1. Short title This Act may be cited as the Big Oil Windfall Profits Tax Act . 2. Windfall profits tax (a) In general Subtitle E of the Internal Revenue Code of 1986 is amended by adding at the end thereof the following new chapter: 56 Windfall profits on crude oil Sec. 5896. Imposition of tax. Sec. 5897. Definitions and special rules. 5896. Imposition of tax (a) In general In addition to any other tax imposed under this title, in each calendar quarter there is hereby imposed on any covered taxpayer an excise tax at the rate determined under subsection (b) on— (1) each barrel of taxable crude oil extracted by the taxpayer within the United States and removed from the property of such taxpayer during the calendar quarter, and (2) each barrel of taxable crude oil entered into the United States during the calendar quarter by the taxpayer for consumption, use, or warehousing. (b) Rate of tax (1) In general The rate of tax imposed by this section on any barrel of taxable crude oil for any calendar quarter is the product of— (A) 50 percent, and (B) the excess (if any) of— (i) the average price of a barrel of Brent crude oil over the covered calendar quarter, over (ii) the average price of a barrel of Brent crude oil over the period beginning on January 1, 2015, and ending on December 31, 2019. (2) Inflation adjustment (A) In general In the case of a calendar quarter beginning in any taxable year beginning after 2022, the amount determined under paragraph (1)(B)(ii) shall be increased by an amount equal to— (i) such dollar amount, multiplied by (ii) the cost-of-living adjustment determined under section 1(f)(3) for the calendar year in which the taxable year begins, determined by substituting 2021 for 2016 in subparagraph (A)(ii) thereof. (B) Rounding If any dollar amount, after being increased under subparagraph (A), is not a multiple of $0.50, such dollar amount shall be rounded to the next lowest multiple of $0.01. (c) Fractional part of barrel In the case of a fraction of a barrel, the tax imposed by subsection (a)