A large McDonald's cup in the United States typically holds between 30 and 32 fluid ounces, depending on the type of drink. For fountain sodas, milkshakes, and iced coffees, the large size is generally 32 ounces. For hot coffee, the large cup is smaller, around 20 to 21 ounces

. To summarize:

• Large soda, milkshake, iced coffee: about 32 oz
• Large hot coffee: about 20–21 oz

Sizes can vary slightly by location and drink type, but 30 to 32 ounces is the standard large cup size for most cold beverages at McDonald's in the US