How To Size Your Kegs Correctly

Over the years, keg sizes have become a somewhat confusing topic for those looking to purchase their own direct draw serving equipment and kegerators for their bar, restaurant, or residence.  After centuries of use in the preparation and storage of alcoholic beverages, the essentially arbitrary sizing system of barrels and kegs has become a bit cumbersome, and the exact meaning of “keg” during a conversation varies depending on the interpretation of the person with which you are speaking. Although keg sizes are not officially standardized from one location to the next, there are generally accepted regional standards that will help make selecting appropriately-sized kegs a simple endeavor.

In the United States, a “barrel” of beer is about 31 U.S. gallons. The keg (with an etymology meaning – quite literally – “small barrel”) is simply a smaller portion of the typical barrel. A standard keg measures ½ barrel, or about 15.5 U.S. gallons. This is easy enough to remember, but where things tend to get a little bit more complicated is in smaller sized kegs. In addition to the literal, size-based names (1/2 keg, 1/6 barrel, etc.) of smaller kegs, most of them also have several nicknames, and keeping up with who calls what keg which name can make keeping track of the sizes a confusing task. Aside from memorizing all of the nicknames, one way to avoid misunderstandings is to keep in mind that terms such as “half keg” refer to a division of the standard keg, not a division of the original barrel size. In other words, a “half keg” is equivalent to a quarter barrel, and should not be confused with the original half barrel size of a standard keg.

Physical size is also important to consider when choosing kegs for your direct draw equipment. Most kegs are limited to a height of about 23-1/8 inches, and most beer units are sized to accommodate. Diameter is more critical, however, as some dispensers are sized to fit several smaller kegs and have shelving that may prevent the storage and use of a single, larger keg. Be sure to familiarize yourself with the size of each keg and verify the design of your equipment before ordering new keg supplies. The following chart gives a general overview of standard keg dimensions. Below is a quick reference chart detailing several standard keg sizes and capacities.