Keg Sizes Table
| Size (US gal) | Liters | 12 oz pours | 16 oz pours | 20 oz pours | Full keg (lb) | Also known as |
|---|---|---|---|---|---|---|
| 1.32 | 5 | 14 | 10 | 8 | — | Mini Keg / Bubba keg (single-use) |
| 3.875 | 14.67 | 41 | 31 | 24 | — | Eighth Barrel |
| 5 | 18.92 | 53 | 40 | 32 | 55–60 | Soda syrup keg / Corny Keg / home brew |
| 5.17 | 19.56 | 55 | 41 | 33 | 58–60 | Sixth Barrel / Torpedo Keg |
| 6.6 | 25 | 70 | 52 | 42 | — | "Half Barrel" (Europe) |
| 7.75 | 29.33 | 82 | 62 | 49 | 90 | Quarter Barrel / Pony Keg |
| 13.2 | 50 | 140 | 105 | 84 | — | Import Keg (standard European half barrel) |
| 15.5 | 58.67 | 165 | 124 | 99 | 140–170 | Half Barrel / Full Keg |
| Content | DIN 6647 height | DIN keg diameter | Euro-Keg height | Euro-Keg diameter |
|---|---|---|---|---|
| 20 L | 310 mm (high) | 363 mm (steel) | 216 mm (high) | 395 mm (steel) |
| 25 L | — | — | 327 mm (high) | 395 mm (steel) |
| 30 L | 400 mm (high) | 381 mm (steel) | 365 mm (high) | 408 mm (steel) |
| 50 L | 600 mm (high) | 381 mm (steel) | 532 mm (high) | 408 mm (steel) |
Keg sizes are fractions of a barrel, and the barrel is not a barrel: in the American beer trade a barrel is a legal 31 gallons, set as a tax unit, which is why the standard party keg is a half barrel at 15.5 gallons - not because anyone splits actual wooden casks. The chart below lays out the whole American ladder from the 5-liter mini through the eighth barrel, the soda-syrup corny keg home brewers love, the sixth barrel that craft breweries standardized on, the quarter-barrel pony keg, the 50-liter European import and the half barrel itself, each with pours at three glass sizes and the full-keg weight you will actually have to move.
The small kegs are the real story of the last twenty years. Before craft beer, bars bought half barrels and restaurants poured from pony kegs; then breweries that sell through taprooms realized the sixth barrel (5.17 gallons, about 55 twelve-ounce pours) matches the freshness window of unpasteurized craft beer and fits a standard tap cooler. European kegs measure in liters - the 50-liter import is 13.2 US gallons, four gallons less than a half barrel, so ordering by the look of the keg instead of the chart leaves four gallons of party short.
How to use
- Buy by pours, not by keg names: a half barrel pours 165 twelve-ounce drinks, a pony keg 82, a sixth barrel 55. For a twelve-person afternoon cookout at three sixteen-ounce pours each, a sixth barrel plus a six-pack backup beats a half barrel that will go flat before it empties.
- Check the freshness math before the price math: keg beer is not bottled beer. Unpasteurized kegs last roughly 45 to 60 days refrigerated before tapping, pasteurized ones three to six months, and once tapped the countdown accelerates to weeks on CO2 and days on a party pump, which injects air.
- Match the coupler and the liters: European kegs are DIN or Euro spec in liters (a 50 L is 13.2 US gallons), use different taps than US Sankey kegs, and their 'half barrel' nickname for the 25-liter size is a courtesy translation, not a barrel fraction.
Frequently asked questions
How many beers are in a keg?
By the standard party math, a full-size half-barrel keg holds 1984 US fluid ounces: 165 twelve-ounce bottles' worth, 124 sixteen-ounce pints, or 99 twenty-ounce pours. The quarter-barrel pony keg runs 82 twelve-ounce drinks, the sixth barrel 55, and the mini keg a modest 14. That pour count is why keg pricing only looks cheap at the big sizes: the half barrel wins on cost per drink, but only if the crowd actually finishes about six and a half cases of beer before it goes flat.
How long does a keg stay fresh?
In three tiers. Untapped and refrigerated, non-pasteurized keg beer - most American craft beer - keeps about 45 to 60 days, while pasteurized kegs last three to six months. Once tapped with a CO2 system the beer stays good for roughly two to three weeks because carbon dioxide neither oxidizes the beer nor carries in flavors. Tapped with a hand pump, the party keg at the picnic, the clock collapses to 8 to 12 hours at full quality and a day or two at all: every squeeze of the pump injects oxygen and airborne wild yeasts, which is why a keg pumped Friday tastes dull by Sunday.
Why is a full keg called a half barrel?
Because the beer barrel is a unit of tax, not a container. The US tax barrel for beer is 31 gallons, a figure carried over from English brewing customs, so a 'full keg' of 15.5 gallons is legally half a tax barrel - the eighth barrel (3.875 gallons) and quarter barrel (7.75) follow the same arithmetic. No one ships 31-gallon steel kegs; the naming is an accounting fossil that survived because excise stamps, distributor pricing and tap rentals were all built around the 31-gallon barrel.
What size keg do I need for 50 people?
Work it in pours: at a typical four-hour party, plan two to three sixteen-ounce drinks per person, so 50 guests means 100 to 150 pours. One quarter-barrel pony keg (62 sixteen-ounce pours) covers the low end; the safe buy is a pony keg plus a sixth barrel (41 pours) for 103, or a single half barrel (124 pours) if the crowd leans heavy. Two smaller kegs beat one large one whenever variety matters - two beers keep more guests drinking their own tab - and the spare keg, kept cold and unopened, keeps for its full 45-to-60-day window.