A half-barrel keg is a common type of beer keg that holds approximately 15.5 gallons, or 58.67 liters, of liquid. This size is often used in bars and restaurants, making it a popular choice for serving draft beer. The half-barrel keg is typically made of stainless steel, which helps preserve the beer's flavor and carbonation. In terms of dimensions, a half-barrel keg usually measures about 23.3 inches in height and 16 inches in diameter. It is designed to fit standard keg taps, allowing for easy dispensing of beer. This keg size is equivalent to about 165 12-ounce servings, making it ideal for parties and large gatherings.