The Starbucks cup size that holds about 31 US fluid ounces is Trenta.
Starbucks introduced the Trenta size in the United States in 2011. Its name comes from the Italian word for “thirty,” reflecting its approximate 30-ounce capacity, although the actual listed capacity is about 31 US fluid ounces. Trenta drinks are generally associated with iced beverages rather than standard hot coffees.
Starbucks’ other commonly recognized sizes include Short, Tall, Grande, and Venti. Short is typically used for smaller hot drinks, while Tall, Grande, and Venti are more prominent on many menus. The Trenta is not simply another hot-cup size; its availability depends on the drink and market.
A common mix-up is confusing Trenta with Venti. Venti is the larger widely used hot-drink size, while Trenta is larger and primarily designed for selected cold drinks.