Black tea, spices and milk
Starbucks makes its chai from black tea infused with cinnamon, clove and other warming spices, combined with steamed milk. The caffeine comes from the black tea, and there isn’t much of it: 25 mg in a Short, 35 mg in a Tall, 55 mg in a Grande and 75 mg in a Venti. The iced version runs a little higher at each size, with 45 mg in a Tall, 60 mg in a Grande and 90 mg in the 24 oz iced Venti.
A Grande chai carries about a third of the caffeine in a Grande Caffè Latte (150 mg), and less than a sixth of a Grande Pike Place Roast at the top of its range (390 mg). It is close to an 8 oz cup of home-brewed black tea, which USDA puts at 47 mg, and a little below a Grande Matcha Latte (65 mg).
A lighter afternoon option
Because it is low in caffeine, chai is a common pick for people cutting back or wanting something warm later in the day, and the numbers support that use. With caffeine’s mean half-life of about five hours (NCBI), a Grande chai at 4 pm leaves under 30 mg in circulation by 9 pm. A Grande Pike Place at the same time leaves somewhere around 160 to 195 mg.
At 55 mg it is also far below the 200 mg single dose EFSA assessed as safe for healthy adults, and seven Grande chai lattes, 385 mg, would still sit under the 400 mg daily figure the FDA cites.
Not caffeine-free
It still counts. Three Venti chai lattes add up to 225 mg, more than the 200 mg daily ceiling ACOG uses in pregnancy. And “chai” means different things at different counters: a café’s chai concentrate or a supermarket spice blend is not Starbucks’ recipe. The figures on this page are Starbucks’ own and apply only to its drinks.