Quick answer: a grande Iced Shaken Espresso at Starbucks has 225 mg of caffeine, and the grande Iced Brown Sugar Oatmilk Shaken Espresso has 255 mg, both per Starbucks' own nutrition pages. That is a full shot more than the iced latte in the same cup.
Why it beats a latte
The shaken espresso is built with one more shot per size than the equivalent latte. A grande iced latte carries two shots at about 150 mg; the grande shaken espresso carries three. The Brown Sugar version runs even higher because it uses Blonde espresso, and Starbucks lists Blonde at more caffeine per shot than the Signature roast, about 85 mg versus 75 mg.
Caffeine by size
| Size | Classic Shaken Espresso | Brown Sugar Oatmilk (Blonde) |
|---|---|---|
| Tall (12 oz, 2 shots) | about 150 mg | about 170 mg |
| Grande (16 oz, 3 shots) | 225 mg, Starbucks-listed | 255 mg, Starbucks-listed |
| Venti (24 oz, 4 shots) | about 300 mg | about 340 mg |
Grande figures are Starbucks' published values; tall and venti follow the menu's shot structure and Starbucks notes all caffeine values are approximate. A decaf version is available and independent lab work has measured decaf espresso at roughly 3 to 16 mg per shot, so decaf is low, not zero.
Looking for a different drink? The full caffeine database has every chain and can we have verified.
Where it sits on the menu
The shaken espresso out-caffeinates the entire latte and mocha family and most cold drinks short of cold brew. If you came from our latte caffeine chart, think of this drink as the latte's stronger sibling in a slightly smaller coat.