It is apparently worth repeating: Different sized cups hold different amounts of liquid.
Starbucks’ coffeehouses sell beverages in a variety of sizes using its trademark paper cups, including the popular “tall” (12-ounces), “grande” (16-ounce), and “venti” (20-ounce) sizes. But according to a popular internet rumor, Starbucks is scamming its customers with this system, because, supposedly, all of its to-go cups hold the same amount of liquid.
In May 2022, a video went viral on Facebook that supposedly showed a person pouring coffee from one cup (A) into another one that appeared larger (B). While one would expect the contents of the small cup (A) to only partially fill up the larger cup (B), the video appeared to show that the same amount of coffee filled both cups to the brim.
This video was deceptively edited. The various cup sizes at Starbucks do not hold the same amount of liquid.
While we’re not entirely sure how the video above was created — our best guess is that the larger cup (B) had a false bottom to take up some volume space — we can say for certain that this video does not accurately represent the amount of liquid in two different sized Starbucks cups. How? Well, this isn’t the first time we’ve seen someone claim that different sized cups hold identical amounts of liquid.
This video is just the latest iteration of an internet prank that has been going around since at least 2016. We first debunked the prank in 2020, after a video went viral on TikTok that supposedly showed how the small, medium, and large cup sizes at McDonald’s hold the same amount of liquid. In 2017, another version of the prank focused on the Jack in the Box restaurant chain.
These videos do not show any type of “scam,” or prove that different sized cups at fast-food restaurants or Starbucks actually contain the same amount of liquid. These videos actually use tricks (some cups may be pre-filled with liquid) or deceptive camera techniques (cups may be switched when they are moved out of frame) to make it appear as though customers are getting the same amount of liquid, no matter what size of cup they order.
In 2018, for example, a YouTuber did this “experiment” using plastic Starbucks cups that the coffee chain uses for its cold beverages.