Caffeine per serving depends far more on how much coffee went in than on how concentrated the drink is.
Rough figures
Single espresso (7–9 g) — 60 to 80 mg Double espresso (18 g) — 120 to 160 mg Mug of filter (250 ml, 15 g) — 90 to 140 mg Large filter (400 ml, 25 g) — 150 to 250 mg Cold brew concentrate, diluted — highly variable, often 150 to 250 mg Instant — 30 to 90 mg
The counterintuitive part
Espresso is far more concentrated — around 8 to 12% dissolved solids versus 1.3% for filter — but the serving is 30 ml rather than 250 ml.
A mug of filter usually has more caffeine than a single espresso.
What actually moves it
Dose. More coffee, more caffeine. This dominates everything else.
Species. Robusta has roughly double arabica.
Ratio and contact time. Longer extraction pulls more, though caffeine extracts early and the effect is modest.
What does not move it much
Roast level. By weight, negligible. By scoop, light roast has slightly more because it is denser.
Grind size, beyond its effect on extraction generally.
Decaf
Not caffeine-free. Typically 2 to 5 mg per cup, occasionally more.
What people want to know
How much caffeine is safe in a day?
The US Food and Drug Administration cites 400 mg a day as an amount not generally associated with negative effects for healthy adults, roughly three to four mugs of drip coffee. Pregnancy, medication and sensitivity change that, so ask a doctor if unsure.
Last reviewed 30 October 2026