How Does Libbey Determine Glass Capacity?

If you’ve ever shopped for a specific type of glassware – say, a double old fashioned – you may have noticed that they come in a wide range of sizes. This style may clock in anywhere from 12 to 14 ounces while still claiming to be a double old fashioned.  

So, how does a glassmaker like Libbey determine the ounce capacity of its glasses?  

When our team creates design concepts, we consider a number of factors, including the standard serving size, the target market for the glass, the potential price for a drink and the possibility for profit at a bar or restaurant.  

During the development process, tooling is designed to produce the glass as intended and at the correct capacity. We then measure the final capacity using the average from a full production run, as the capacity for each piece can vary slightly, up to 5 percent. Glasses are pulled dozens of times an hour to confirm capacity. 

When setting the final capacity, we measure to overflow, meaning when liquid is above the rim of the glass just before it spills over the side. The measurement is calculated using the weight of water in the glass and is very accurate. 

Libbey also sizes glasses to account for spillage and other factors. Though a standard pint of beer is 16 ounces, it must be served in a larger glass to leave room for the head of foam and the ability of a server or customer to carry it to a table without losing any liquid. 

Whether you’re sipping wine, a cocktail or beer, our goal is to create glassware that is just the right size for the drink and brings the best out of every beverage.