Barrel Volume and Capacity Calculator

Find the cubic footage and total volume of a barrel and get the capacity in gallons and liters.


How to Find the Volume of a Barrel

A barrel is a round container that is wider in the middle than at the top and bottom. They are generally made of wooden slats called staves that are held together with metal hoops. Barrels are generally used to store beverages such as wine, beer, and liqueurs. The average size of a 53 gallon whiskey barrel is 36″ high with a top and bottom diameter of 21″ and a middle diameter of 26″.

To find the volume of a barrel you will need to know its height, radius at the top and bottom, and radius in the middle. Use these values with the following formula for the total volume of a barrel:
volume = (h × &pi × ((2 × r22) + r12)) ÷ 3
h = height
r1 = top/bottom radius
r2 = middle radius

drawing of a barrel showing how to find the height, middle radius, and top/bottom radius

To use this formula ensure that the height, top/bottom radius, and middle radius values are all in the same unit of measure, inches are most commonly used. Often the volume of a barrel will be expressed in cubic feet or cubic meters while the capacity of a barrel will be expressed in gallons or liters.

If all dimensions used in the formula are in inches then the total volume measurement will be in cubic inches. To get the total volume in cubic feet convert from cubic inches using the formula ft3 = in3 × 0.000578704. Use our cubic inches to cubic feet calculator to quickly convert.

Example: For a 53 gallon whiskey barrel with a height of 36″, a top/bottom diameter of 21″, and a middle diameter of 26″

top/bottom radius = 21 ÷ 2
top/bottom radius = 10.5

middle radius = 26 ÷ 2
middle radius = 13

volume = (h × π × ((2 × r22) + r12)) ÷ 3
volume = (36 × π × ((2 × 132) + 10.52)) ÷ 3
volume = (36 × π × ((2 × 169) + 110.25)) / 3
volume = (36 × π × (338 + 110.25)) ÷ 3
volume = (36 × π × 448.25) ÷ 3
volume = 50694.4 ÷ 3
volume = 16898.1 in3
16898.1 in3 = 9.8 ft3

How to Find the Capacity of a Barrel

The capacity of a barrel is often measured in gallons or liters. To find the capacity of a barrel simply convert the total volume to gallons or liters. Gallons can be found using the formula gallons = ft3 × 7.480507. Use our cubic feet to gallons calculator to easily make this conversion.

To find the capacity in liters use the formula liters = ft3 × 28.3168. We also have a cubic feet to liters calculator to make this easy.

Finding the volume of a barrel is relevant when measuring the amount of beverage it contains. This is useful for beer-making, wine-making, and measuring other beverages. Use our volume calculator to find the volume of many other shapes.