Barrel Volume Formula & Calculator


Online Barrel Volume Formula & Calculator: Calculate the volume of a Barrel based on its middle radius, height and top & bottom radius. Enter three unknowns in the form and press the CALCULATE button.

Table of contents:

Definition of the word Barrel

Unit of measure of the volume of crude oil which is equivalent to approximately 159 liters (0.159 m3). The Anglo-Saxons imposed barrel as the benchmark unit of measurement in the oil industry. Its origin can be traced back to the wooden barrels that were used to transport salt, or herring to the United States and which were also initially used to transport crude oil.

Calculate the Volume of a barrel

Historically, determining the volume of a barrel has been problematic. A simple method, but restrictive, consists of pouring buckets of which one knows the capacity and counting how many ones can pour.

But it quickly appeared simpler to use a formula that would express the volume V 'of a barrel according to the three dimensions indicated in the diagram above: the height h of the barrel (distance between the two bottoms), its diameter maximum D, and it's minimum diameter d. The thickness and any irregularities in the barrel wall are neglected; it is considered that the lower and upper bases are identical and that the section of diameter D (called barrel swing) is located halfway up the barrel.

Barrel volume formula

Johannes KEPLER (German mathematician and astronomer, 1571-1630) established the following formula to calculate an approximate value V of the volume of a barrel:

Barrel Volume =(πh/12) x (2D2 + d2)

h: height

D: middle radius

d: top & bottom radius

What is an “oil equivalent” barrel?

Like the "oil equivalent" tonne, the "oil equivalent" barrel is a conventional unit allowing the comparison between different energy sources, in particular between oil, natural gas, and coal.

The different quantities of fossil fuels can thus be reduced to the number of units of crude oil that have the same calorific value. In particular, this allows oil and petroleum groups to express in the same unit their production or their reserves of oil and natural gas and to add them up in their balance sheets.

Oil volumes are often expressed in barrels (nearly 159 liters). The density of oil varies and the International Energy Agency (IEA) uses as a convention that one ton of oil contains about 6.84 barrels (BP uses as a convention 1 ton of oil = 7 barrels).

The IEA thus retains the following equivalences:

1 boe = 0.146 toe = 161 m3 of gas;

1,000 m3 gas = 6.2 boe.

The most common types of barrels

Bulk barrel, which is worth 5.8 or 5.0 cubic feet (164.238 liters);

Imperial barrel, which is worth 36 imperial gallons (163.659 liters);

U.S. proof spirit barrel, which is worth 40 U.S. gallons (151.416 liters);

U.S. fluid barrel, which is worth 31.5 U.S. gallons (119.240 liters);

U.S. dry barrel, which is worth 105 U.S. dry barrels (115.628 liters);

U.S. cranberry barrel, which is worth either 86 and 45⁄64 U.S. dry pints (95.479 liters), or 5,826 cubic inches (95.471 liters).