How Much Beer Is In A Keg?

A full-size US keg, the half barrel, holds 15.5 gallons of beer. That is 1,984 fluid ounces, about 165 twelve-ounce servings or 124 pints, and at 5% ABV it is 165 standard drinks. Every other keg is a fraction of that, and the names (pony, sixtel, corny, mini) tell you which fraction once you know the code. Here are all the sizes with servings, standard drinks, weights and dimensions, how many people each one serves, how long a tapped keg stays fresh, and the rules that apply when you buy one.

Last verified September 13, 2026. Keg sizes are from 27 CFR 25.11 and 25.156, standard-drink figures from NIAAA and CDC, dimensions and empty weights from keg manufacturers (Thielmann and Blefa), serving and storage guidance from the Brewers Association and Micro Matic. Full list at the end.

Why a keg is measured in barrels

Federal law defines a barrel of beer as exactly 31 US gallons (27 CFR 25.11). That is the unit breweries pay federal excise tax on, and it is why keg sizes are named as fractions of a barrel rather than in round gallons. Nobody sells a full 31-gallon barrel as a keg. The biggest keg you will see is the half barrel, and the tax rules (27 CFR 25.156) also recognize thirds, quarters, sixths and eighths, plus three metric sizes: 5 gallons, 30 liters and 50 liters.

Keg sizes and how much beer they hold

Servings are rounded down. Standard drinks assume 5% ABV beer, where a 12 oz serving is exactly one standard drink (0.6 fl oz of pure alcohol, per NIAAA and CDC). A 7% IPA in the same keg is 40 percent more standard drinks; a 10% beer is double.

The math: 1 US gallon is 128 fl oz and 3.785 L (NIST Handbook 44), so a half barrel is 15.5 x 128 = 1,984 oz; divide by 12 for servings and by 16 for pints. The Brewers Association’s retailer manual counts a half barrel as 132 pints rather than 124, because a proper pint pour is 15 oz of beer under three quarters of an inch of foam.

Two things the names hide. A sixth barrel (5.17 gal) and a Cornelius keg (5.0 gal) are not the same keg: they differ by about two servings and, more to the point, use different valves, a Sankey D coupler on the sixtel and ball-lock or pin-lock posts on the corny. And a quarter barrel comes in two shapes that hold the same beer: the short, wide pony keg and the slim quarter, which is as tall as a half barrel but narrower, so it fits a kegerator.

Weights and dimensions

Heights, diameters and empty weights are manufacturer figures (Thielmann for US and Euro kegs; Kegworks retailer listing for the Cornelius). Full weights are computed at 8.34 lb per gallon, since beer weighs within about 1 percent of water, and rounded.

A full half barrel is a two-person lift. It is also worth knowing that a half barrel, a slim quarter and a sixtel are all the same height, so any of the three stands in a standard kegerator; only the width changes.

How many people does a keg serve?

This is pure division: servings in the keg divided by drinks per person. The table uses 12 oz servings. For pints, use the pint column above.

So a half barrel covers a four-hour party of about 40 people at four beers each, or 55 people at three. Those figures assume everyone is drinking beer and nothing else; if there is wine or a cocktail on the table, the keg goes further. Expect to lose a few servings to foam and to the first pours off a fresh tap. And remember that a keg is a fixed quantity sitting in the room. Unlike cans, it does not run out one at a time, and a tap has no jigger, so plan the guest list to the keg rather than the keg to the guest list.

How long a keg stays fresh

The Brewers Association’s guidance for retailers is that every keg must be at or below 38 F when it is served, and that a rise of even a few degrees above 38 F creates pouring problems, mostly foam. Most draft beer, from large domestic breweries and most craft breweries alike, is not pasteurized, which is why temperature and the gas you push it with matter so much.

The hand-pump number is the one that matters for a party. A party pump pushes room air into the keg, and air is what turns beer flat and stale, so a keg tapped with a pump is a same-day keg. If you want leftovers the next weekend, you need CO2. Keep the keg on ice from the moment it arrives, not from the moment you tap it.

What goes into the cost of a keg

Keg prices change by beer, by store and by state, so we do not print them. What is stable is what shows up on the receipt beyond the beer itself:

• The deposit. Retailers charge a refundable deposit on the keg shell and, usually, a separate one on the tap. Both come back when the equipment does.
• The tap. A hand-pump party tap is normally rented with the keg. The sixtel and the other US kegs in the table use a Sankey D coupler, Cornelius kegs use ball-lock or pin-lock posts, and imported Euro kegs may need a different coupler, so confirm the tap matches the keg.
• Ice. Keeping a half barrel at 38 F takes a tub and a lot of ice, and that is its own line item.
• Federal excise tax. Beer is taxed by the barrel before it reaches the store: $18.00 per barrel at the general rate, $16.00 on the first 6 million barrels for larger brewers and importers, and $3.50 on the first 60,000 barrels for brewers making no more than 2 million barrels a year. On a half barrel that is $9.00, $8.00 or $1.75 of federal tax, built into the price (TTB rates, 26 U.S.C. 5051).

Keg registration laws

Many states require keg registration. In a registration state the retailer attaches a numbered tag to the keg and records the buyer’s name, ID number, address and the address where the keg will be consumed, so a keg found at an underage party can be traced to the adult who bought it. Sixteen of those states also prohibit possessing an unregistered keg. The size threshold varies; states set it anywhere from about 2 to 8 gallons, so a sixtel may or may not be covered where you live.

As of January 2018, 30 states and the District of Columbia had keg registration laws, according to NIAAA’s Alcohol Policy Information System as cited by County Health Rankings, and Utah bans keg sales outright. We could not confirm a more recent count against APIS at verification time, and states change these laws, so treat the number as a 2018 figure and check your state ABC before buying. Wherever you are, the store will ask for ID, and the registration form is a legal requirement on the buyer, not a store policy.

Frequently asked questions

How many beers are in a keg? 165 twelve-ounce beers in a half barrel, 82 in a quarter barrel, 55 in a sixth barrel, 14 in a 5 L mini keg.

How many cases is a keg? A half barrel holds 1,984 oz, and a 24-pack of 12 oz cans holds 288 oz, so a full keg is a little under seven cases (6.9). A quarter barrel is about three and a half cases; a sixtel is about two and a third.

Is a keg 31 gallons? No. A barrel is 31 gallons. The full-size keg is a half barrel, 15.5 gallons.

How much does a full keg weigh? About 159 lb for a half barrel (30 lb empty plus 129 lb of beer), about 88 lb for a quarter barrel, about 56 lb for a sixtel.

How many standard drinks are in a keg? At 5% ABV, the same as the number of 12 oz servings: 165 for a half barrel. Multiply by ABV divided by 5 for anything stronger; a 7% beer makes a half barrel 231 standard drinks.

Does a keg need to be cold before tapping? Yes. The Brewers Association’s serving standard is 38 F or below, and a warm keg foams. Ice the keg for several hours before the first pour.

Sources

• 27 CFR 25.11, Meaning of terms, barrel and beer (eCFR), checked September 13, 2026
• 27 CFR 25.156, Determination of tax on keg beer (eCFR), checked September 13, 2026
• 27 CFR 25.152, Reduced rate of tax for certain brewers (eCFR), checked September 13, 2026
• TTB tax and fee rates, checked September 13, 2026
• Brewers Association, Draught Beer Quality for Retailers (2022), checked September 13, 2026
• Micro Matic, How long will a keg of draft beer remain fresh, checked September 13, 2026
• Thielmann US standard kegs (dimensions and tare) and Thielmann Euro kegs, checked September 13, 2026
• Blefa USA half-barrel keg specifications, checked September 13, 2026
• Kegworks, Guide to beer keg sizes (retailer listing, used for Cornelius and mini keg dimensions), checked September 13, 2026
• County Health Rankings, Keg registration laws (citing NIAAA APIS, January 2018), checked September 13, 2026
• NIAAA, What is a standard drink and CDC, Standard drink sizes, checked September 13, 2026
• NIST Handbook 44, Appendix C (gallon conversions), checked September 13, 2026

Can you get a keg delivered?

Kegs are not something we deliver; the independent shops that fill Saucey orders sell beer by the can, bottle and case, and some list 5 L mini kegs. What is available depends on your address. Enter it and we will show you what is in stock nearby at saucey.com/beer, delivered in as fast as 25 mins in the cities we serve.

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