How Many Beers in a Keg?
Choose the keg and the size of the cup you pour. You get the whole servings, plus pints, 8 oz cups, gallons and liters, and a table for every keg size.
How to use this calculator
- Under “Keg size”, choose from the list: half barrel, quarter barrel, slim quarter, sixth barrel, 50-liter, 5-gallon ball-lock, or mini keg.
- Under “Cup size”, enter the size and pick its unit: fl oz, mL, or L. The default is 16 fl oz, which is a US pint.
- Open “More options” and enter “Foam and waste (%)”. It starts at 0. The tool does not supply a figure, so enter one based on your own experience or a source you trust. A value of 100 or more is rejected, and a value above 25 shows a warning.
- Read “Servings from one keg” first. This is the count after partial cups are dropped.
- Check the other outputs: “Full 16 fl oz pints”, “US cups (8 fl oz each)” (shown without rounding), “Beer poured”, “Keg volume (US gallons)”, and “Keg volume (liters)”.
- If the warning appears that the cup is larger than the whole keg, choose a smaller cup size or a larger keg.
- For a quick start, use a preset: half barrel 16 oz, half barrel 12 oz, sixth barrel 16 oz, or quarter barrel 16 oz.
- To compare cup sizes at once, use the table. It lists every keg size against cups of 12, 16, 20, 22, and 24 fl oz, with the same waste percentage applied to each row.
The page keeps your settings in its link, so you can bookmark the link or send it to someone with the same inputs already filled in.
How many beers are in a keg?
A keg holds a fixed volume, and the number of servings is that volume divided by one cup size. The tool uses this formula: servings = floor(keg fl oz x (1 - waste%/100) / cup fl oz). The floor function drops any partial cup, so only complete cups are counted.
How many ounces are in a keg?
The cup sizes are measured in fluid ounces, so every keg is converted to fluid ounces first. One US gallon equals 128 fl oz. A half barrel of 15.5 US gallons holds 15.5 x 128 = 1,984 fl oz. A quarter or slim quarter keg of 7.75 gallons holds 992 fl oz, and a 5-gallon ball-lock holds 640 fl oz.
How many gallons are in a keg?
Keg sizes are listed in US gallons, and a 50-liter keg or a mini keg is listed in liters. A barrel is 31 US gallons under 27 CFR 25.11, so a sixth barrel is 31/6 = 5.1667 gallons. Some sources round this to 5.16 gallons, but the tool uses the unrounded value, which gives 661.33 fl oz. Sources also disagree on the mini keg, listing 1.32 gallons and 1.75 gallons. Both list 5 L, so the tool uses 5 L, which is about 1.321 US gallons.
How many pints are in a keg?
A pint in this tool means a 16 fl oz cup, which is a US pint. An 8 fl oz cup is a US cup. A half barrel holds 1,984 / 16 = 124 pints, and 1,984 / 12 = 165 servings at 12 fl oz. Metric cups convert by their fluid-ounce value: a 355 mL cup counts as 12.0035 fl oz, and a 500 mL cup counts as 16.91 fl oz. A quarter barrel with a 500 mL cup gives 992 / 16.91 = 58 servings.
Why does the waste percentage change the count?
Waste lowers the usable volume before the division happens. A sixth barrel at 16 fl oz with 10% waste gives 661.33 x 0.9 = 595.2 fl oz, which divides into 37 servings. The waste percentage defaults to 0 because the tool was not built on a public source with a typical foam or line-loss figure. The result is only as good as the number you type.
What happens to a partial cup?
A partial cup is dropped rather than rounded up. A quarter barrel with a 500 mL cup gives 992 / 16.91 = 58.66 cups, and the tool shows 58 servings. The unrounded “US cups (8 fl oz each)” output still shows the fraction, so you can see how close the keg is to one more serving.
Sources (checked 15 October 2026): nist.gov · law.cornell.edu · kegworks.com · cdn.brewersassociation.org
Worked examples
| Input | Result |
|---|---|
| Half barrel (full size), 16 fl oz cups, 0% waste | 124 servings |
| Half barrel (full size), 12 fl oz cups, 0% waste | 165 servings |
| Sixth barrel (sixtel), 16 fl oz cups, 10% waste | 37 servings |
| Quarter barrel (pony or stubby), 16.91 fl oz cups, 0% waste | 58 servings |
Calculated by the tool above; open it with the same values to see each step.
Frequently asked questions
How many pints in a keg does a half barrel hold?
A half barrel holds 1,984 fl oz, which gives 124 full 16 fl oz pints. With 12 fl oz cups, the same keg gives 165 servings.
How many ounces in a keg is a sixth barrel?
A sixth barrel holds 661.33 fl oz, based on 31/6 US gallons. Some sources round this to 5.16 gallons, but the tool uses the unrounded figure.
How many gallons in a keg is a mini keg?
A mini keg is 5 L, which is about 1.321 US gallons. Sources list 1.32 and 1.75 gallons, but both list 5 L, so the tool uses the liter value.
Why does my count differ from a chart?
Check the cup size, the unit, and the waste percentage first. The waste percentage defaults to 0, so an unchanged figure gives a higher count than one with a foam allowance.
Can I enter a cup size in mL?
Yes. Choose mL or L as the unit. A 355 mL cup counts as 12.0035 fl oz, and a 500 mL cup counts as 16.91 fl oz.
Does this tool check any serving rules?
No. It only does volume arithmetic. It does not check food-safety limits or any rules about serving drinks.
Is anything I enter uploaded?
No. The calculation runs in your browser, and nothing is uploaded.
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