What Is the Keg Volume Calculator?
This calculator tells you how many beers you can pour from a keg. Pick a standard keg size — or enter a custom volume — and your serving size in fluid ounces, and it returns the number of servings along with the total volume in gallons, fluid ounces, and liters. It's perfect for planning a party, stocking a bar, or estimating cost per pour.
How to Use It
1. Choose a keg size. Common US options include the full barrel (15.5 gal), quarter barrel (7.75 gal), sixth barrel/sixtel (5.16 gal), Cornelius keg (5 gal), and the 50 L Euro keg (≈13.2 gal). 2. If you select "Custom," type your own gallon volume. 3. Enter how many fluid ounces are in one serving — a standard US pint is 16 oz, a typical bar pour is often 12 oz. Click calculate to see your results.
The Formula Explained
Since there are 128 fluid ounces in one US gallon, the total volume in ounces is the gallons times 128. Dividing that by the ounces in a single serving gives the number of beers:
$$\text{Beers} = \frac{V_{\text{gal}} \times 128}{\text{oz}_{\text{per beer}}}$$
Liters are found with \(1\text{ gallon} = 3.78541\text{ L}\).
Worked Example
A full-size half barrel keg holds 15.5 gallons. Total ounces = \(15.5 \times 128 = 1{,}984\text{ fl oz}\). Serving 16 oz pints: \(1{,}984 \div 16 = \textbf{124 beers}\). If you pour 12 oz servings instead: \(1{,}984 \div 12 \approx 165\text{ beers}\). The keg also equals \(15.5 \times 3.78541 \approx 58.67\text{ liters}\).
FAQ
How many beers in a standard keg? A full-size half barrel (15.5 gal) yields about 124 sixteen-ounce pints or roughly 165 twelve-ounce servings.
Does foam reduce the count? Yes — real-world pouring loses beer to foam and waste, so plan for 5–10% fewer servings than the math suggests.
What size is a "sixtel"? A sixth barrel holds about 5.16 gallons, roughly 41 sixteen-ounce pints.
