The foam doesn’t change the dose
Starbucks’ Espresso Macchiato is a shot (or several) “stained” with a small dollop of foamed milk, and the caffeine tracks the shots exactly: 75 mg for a Solo, 150 mg for a Doppio (the default order), 225 mg for a Triple, and 300 mg for a Quad, identical to ordering Starbucks Espresso straight. The milk adds volume and a little sweetness on top, nothing more.
This is the same style as a traditional macchiato, which USDA measures at a broadly similar 85 mg for a 2 oz cup. It is a different drink altogether from Starbucks’ better-known Caramel Macchiato, which is built more like a latte and carries 150 mg in a Grande on its own separate size scale.
Two drinks share one name
Because “macchiato” means different things depending on the order, it is worth being specific at the counter. Ask for an Espresso Macchiato and the size (Solo through Quad) sets the dose in fixed 75 mg steps. Ask for a Caramel Macchiato and the standard Starbucks cup sizes (Tall, Grande, Venti) apply instead.
Because the caffeine is entirely in the shots, splitting a Doppio between two people, or asking for a Solo instead, is a straightforward way to halve the dose without changing the drink’s character.
Where it fits in a day
A Doppio, 150 mg, sits under the 200 mg single dose EFSA assessed as safe for healthy adults; a Triple (225 mg) goes over it. A Quad, 300 mg, is three-quarters of the 400 mg daily figure the FDA cites for healthy adults.