No, Starbucks Cup Sizes Do Not Hold the Same Amount of Liquid

A viral claim circulating on Instagram and TikTok asserts that Starbucks’ cup sizes: Tall (12 oz), Grande (16 oz), and Venti (20 oz), contain the same amount of liquid, implying that customers are being misled into paying more for larger sizes that provide no extra volume.

Social Media Post

Recently, a viral video appearing to show liquid from a smaller cup completely filling a larger one has sparked widespread discussion.

Source | Archive

Fact-Check

Starbucks clearly defines its handcrafted drink sizes as follows: Short (8 oz), Tall (12 oz), Grande (16 oz), Venti Hot (20 oz), Venti Cold (24 oz), and Trenta (30 oz). These measurements are standardized and publicly available on Starbucks’ website and in-store materials, leaving little room for ambiguity about the intended capacity of each cup. (Source)

There are also videos claiming Starbucks cup sizes hold the same amount (see example here and here), those fail to show whether the cups are truly empty before liquid is poured, raising suspicions of tampering or deliberate misrepresentation. In some cases, the pouring process is edited or obscured, undermining the credibility of the demonstration.

Independent testing by Tasting Table showed clear differences in capacity: when liquid from a Tall cup (12 oz) was poured into a Grande cup (16 oz), it left approximately an inch of empty space, with even more unfilled space in a Venti cup (20 oz). This aligns with basic physics, and while Starbucks’ cups have slight variations to accommodate foam, ice, or toppings (e.g., Venti Cold at 24 oz), these differences are openly communicated and don’t affect the standard liquid capacity.

Another video experimenting with Starbucks cup sizes, inside a Starbucks location, shows that hot tall-size drinks usually aren’t filled to the cup’s full capacity. When the creators poured these drinks into bigger sizes, it clearly demonstrated that the cups contain different amounts of liquid.

Moreover, a Starbucks barista conducted the same experiment on her TikTok channel, coldbrewmust, which also shows that the cup sizes hold different amounts. Her video caption reads “A good friend sent me a video about ‘All sizes are same for coffee. Dirty business!’ Here’s your answer…”

https://www.tiktok.com/@coldbrewmust/video/7105926088546733358

Summary

Multiple independent tests have examined the viral claim that Starbucks cup sizes hold the same amount of liquid. Testing shows that each cup size: Tall (12 oz), Grande (16 oz), and Venti (20 oz), holds different volumes that match their advertised measurements.