A standard eight-ounce cup of drip coffee has roughly 95 mg of caffeine. That’s the number to carry around, and everything else is a variation on it.
“Roughly” is doing real work in that sentence. The bean, the roast, the grind, the brew time and how big your mug actually is all move it. Published figures for a cup of coffee range from about 70 to 140 mg, and they’re all telling the truth about something.
- Drip coffee, 8 oz
- about 95 mg
- Espresso, single shot
- about 63 mg
- Latte or cappuccino
- about 63 mg (one shot) or 125 mg (two)
- Instant coffee, 8 oz
- about 60 mg
- Cold brew, 8 oz
- roughly 100–200 mg, depending entirely on dilution
- Decaf, 8 oz
- about 2 mg — low, not zero
- Black tea, 8 oz
- about 47 mg
The espresso thing, which nearly everybody has backwards
A shot of espresso has less caffeine than a cup of drip coffee. About 63 mg against about 95.
Espresso is far more concentrated — there’s much more caffeine per ounce. But there is only one ounce of it, and a mug of drip is eight. Concentration and quantity are different things, and the word “strong” unhelpfully means both.
So the double espresso somebody orders to really wake up is about the same as the filter coffee next to it. Ordering a bigger latte doesn’t help either — that’s more milk around the same shots. Ask for an extra shot instead. More of this in what espresso actually is.
Light roast, dark roast
Roasting burns off a little caffeine, so light roast has marginally more by weight. The difference is small enough to ignore, and it is the reverse of what dark-roast packaging tends to imply.
Cold brew is the wild card
Made as a concentrate with a great deal of coffee, then diluted — or, in a lot of cafés, not diluted enough. That’s why cold brew has a reputation for hitting hard. It isn’t the cold water; it is how much coffee went in. The comparison with iced coffee is here.
How much is too much
The FDA puts 400 mg a day — four or five cups of drip coffee — as the amount not generally associated with problems for healthy adults. Pregnancy guidance is lower, usually around 200 mg, and that’s a conversation for a doctor rather than a coffee company.
Caffeine also has a half-life of around five hours, meaning half of your 3 p.m. coffee is still in you at 8 p.m. If you sleep badly and drink coffee in the afternoon, those two facts are probably related.
Where these numbers come from
Figures above are the widely published averages from the US Food and Drug Administration and the USDA food composition database. Treat them as good averages rather than measurements of the specific cup in front of you.