How many ounces are in a Starbucks tall frappuccino?

12 fluid ounces

Rest of the in-depth answer is here. Also know, how many ounces is a tall at Starbucks?

12 ounces

Additionally, why are Starbucks sizes the way they are? Grande is Italian for 'large,' venti means 'twenty,' and trenta is 'thirty'. The sizes originated when Howard Schultz, the founder of Starbucks, opened his first coffee shop in Seattle in 1986. The shop, called Il Giornale, had just three sizes: short, tall, and grande.

Also know, how many ounces are in a tall frappuccino?

12 ounces

Why are Starbucks sizes tall grande and venti?

A short essentially correlated with a small, a tall was a medium, and a grande was a large. The introduction of the venti size demoted the tall—making it the new short—and removed the short size altogether.