Video proves all sizes of Starbucks’ paper drink cups hold the same amount of liquid.

A viral video claimed Starbucks customers are being scammed because all of the coffee chain’s cup sizes hold the same amount of liquid. But does this buzzworthy claim hold up?

An April 28 Instagram reel showed a person pouring coffee from a tall cup of coffee, which is Starbucks’ small size, into an empty grande cup, equivalent to medium. The grande cup appears to be filled to the brim. Then, the person pours the coffee back into the tall cup, supposedly showing that the two cups hold the same amount of coffee.

The person then pours the contents of the tall cup into a venti, Starbucks’ large size, cup. Once again, the cup appears to be filled to the brim with coffee.

(Screengrab from Instagram)

“You might think it’s some kind of trick — and it is — but it’s not a magic trick. It’s a marketing trick. And Starbucks gets all the credit,” the person in the video says. “This is how they put the ‘bucks’ into ‘Starbucks.’”

The post’s caption reads, “(You’re) getting the same size but paying more seems like robbery to me.”

The post was flagged as part of Meta’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook and Instagram.)

PolitiFact tested this claim ourselves.

(PolitiFact photo)

We went to a nearby Starbucks and requested three empty paper cups used for hot drinks in the same sizes seen in the video: tall, grande and venti.

We filled the tall cup to the brim with water, then poured its contents into the grande cup. The water did not reach the top, showing that the grande cup is, in fact, bigger than the tall cup.

We also tested the venti cup. We poured water from a full tall cup into the venti cup and, again, the contents did not reach the top. The water line was lower on the venti cup than on the grande cup, showing that it is the biggest of the three cups.

(PolitiFact photo)

To be certain, we filled the tall, grande and venti cups to the brim with water and then, one at a time, measured the amount of water in each with a measuring cup. The tall cup held about one and two-thirds cup of water. The grande cup held more than two cups, which is the highest line on the measuring cup. And the venti cup’s content filled the measuring cup to the brim.

Starbucks’ menu says this is how much each of its cups hold:

• Tall, 12 ounces

• Grande, 16 ounces

• Venti, 20 ounces

It’s unclear how the person in the video performed this coffee cup trick.

Verify, Snopes and BuzzFeed fact-checked similar false claims that Starbucks cups were all the same size.

We rate the claim that a video proves all of Starbucks’ paper drink cups hold the same amount of liquid Pants on Fire!