Calculate Liters in a Barrel, Cask or Keg

Calculator how many liters fit in a barrel, cask or keg of a certain size or what size the barrel needs to be.

The size of a barrel (or cask or keg) is precisely determined by specifying the upper and lower as well as the middle diameter and the height. The measurement must be made inside the barrel, not outside. The upper and lower diameters are the same, the middle one is larger. For the mathematical background, see barrel (geometry).

Example: a barrel with a diameter of 60 cm at the top and bottom, 70 cm in the middle and 80 cm high has a capacity of over 280 liters.

Please enter any three values. This can be both the diameter and height of the barrel, or two of these values and the volume. The fourth value will be calculated.

The formula for calculating the volume of a barrel from the diameter and height is:
V = π * h * ( D²/2 + d²/4 ) / 3
with height h, mean diameter D and upper and lower diameter d.

Calculating the volume of a barrel that is only partially filled is very complicated and requires higher mathematics, at least when the barrel is not half full. In the latter case, the volume is also halved, with the volume of a barrel filled to a third of the height being less than a third. If it is two-thirds full, the volume is more than two-thirds.

This barrel, about 1.20 meters high with a top and bottom diameter of 50 centimeters and a middle diameter of 60 centimetres, holds a bit more than 300 liters.