A measure of the amount of a combustible material which when burnt releases the same amount of energy as the combustion of one barrel of crude oil. Multiplications of this unit include kilo, million, and billion barrels of oil equivalent (kBOE, MBOE, BBOE). It is also expressed as a rate such as million barrels oil equivalent per day (MBOED). It is used for financial purposes to combine both oil and gas into a single measure.