Coffee and caffeine
How much caffeine is in coffee?
There is no single number for a cup of coffee. Size, beans, and brewing method all change the result.
Open the free caffeine tracker
Useful starting points
These are approximate figures for the servings shown. They help you get oriented, but they are not a lab result for the cup in your hand.
| Drink | Serving | Approximate caffeine |
|---|---|---|
| Filter coffee | 200ml | 90mg |
| Espresso | 60ml | 80mg |
| Regular brewed coffee | 12 fl oz | 113–247mg |
| Decaf coffee | 8 fl oz | 2–15mg |
The filter and espresso figures come from EFSA. The brewed-coffee range and decaf range come from the FDA. The serving sizes are different, which is one reason “a cup” can be misleading.
Why the number changes
Caffeine depends on the amount of coffee used, the bean variety, the grind, the water, and the time and method of extraction. A small espresso is concentrated, but a large filter coffee can contain more caffeine overall because it is a larger serving and may use more coffee.
Real cups vary more than most menus suggest. One study tested 97 espresso samples from coffee outlets and found 25–214mg per serving. Another study found six-fold differences between 20 commercial espressos. The label or the café’s own information is the best answer when it is available.
Decaf does not mean caffeine-free. It usually means less caffeine, and the amount still varies.
Estimate your own brew
SlumberBrew’s brew calculator uses the details you actually know: the method, the amount of coffee, or the water-to-coffee ratio. It gives a range because the same recipe can produce different cups.
Then the tracker puts that estimate on a timeline. You can see what may be left at bedtime instead of relying on a generic number for “coffee”.
Calculate your coffee and bedtime estimate
Common questions
Does a bigger cup always have more caffeine?
No, but size matters. A larger serving often contains more coffee or a double shot, while recipes and strength vary. Compare the actual serving size rather than the word “coffee”.
Is decaf coffee caffeine-free?
No. The FDA gives 2–15mg as a typical range for an 8-fluid-ounce cup of decaf coffee. Some people who are very sensitive to caffeine may still notice it.
How much caffeine is too much?
EFSA and the FDA cite up to 400mg across a day as an amount not generally associated with negative effects for most healthy adults. EFSA uses a lower 200mg daily figure for pregnancy. Sensitivity, health conditions, and medicines can change what is right for you. Read more about choosing your dose.
Sources
- European Food Safety Authority: Caffeine — approximate amounts for filter coffee and espresso, plus intake guidance.
- US Food and Drug Administration: How Much Caffeine Is Too Much? — brewed-coffee and decaf ranges, and practical guidance.
- Desbrow et al. (2007) — caffeine variation across 97 espresso samples.
- Crozier et al. (2012) — six-fold differences across 20 commercial espresso coffees.
How long does caffeine stay in your system? · How much caffeine should you have? · Use the caffeine cutoff calculator · Caffeine and sleep