The EFSA assessment: where the limits come from
In 2015, the European Food Safety Authority (EFSA) assessed the safety of caffeine in a scientific opinion. The key statements for healthy people:
- Adults: Single doses of up to 200 mg (about 3 mg per kg of body weight) and up to 400 mg spread over the day are considered safe.
- Pregnant and breastfeeding women: Up to 200 mg spread over the day is considered safe for the fetus or the infant.
- Children and adolescents: Lacking sufficient data, EFSA derives a guidance value of 3 mg per kg of body weight per day.
These values are not prohibition thresholds but amounts at which EFSA sees no health concerns. Sensitivity is individual: some people feel palpitations after a single cup of coffee, others tolerate considerably more.
Caffeine table: typical amounts
Rounded guidance values, real products vary by variety and preparation:
| Drink / food | Caffeine |
|---|---|
| Filter coffee (cup, 200 ml) | approx. 90 mg |
| Espresso (60 ml) | approx. 80 mg |
| Black or green tea (cup, 220 ml) | approx. 50 mg |
| Energy drink (can, 250 ml) | approx. 80 mg |
| Cola (can, 355 ml) | approx. 40 mg |
| Dark chocolate (half a bar, 50 g) | approx. 25 mg |
| Milk chocolate (half a bar, 50 g) | approx. 10 mg |
In the EU, energy drinks are capped at 320 mg of caffeine per liter, so a 250 ml can contains at most 80 mg. Decaffeinated coffee contains caffeine too, by the way, though only a few milligrams per cup.
Caffeine and sleep: the underrated math
Caffeine has a half-life of about 4 hours on average, with a wide individual range of 2 to 8 hours. Of the 90 mg from an afternoon cup at 4 pm, around 30 to 45 mg are often still active at 10 pm. If you have trouble falling asleep, an earlier caffeine cutoff usually gains you more than any evening routine. In moderation and at the right time, on the other hand, there is little to be said against coffee and tea for healthy adults, and they count toward your fluid intake too, as the water intake calculator shows you.
Do not forget the sugar
With cola and energy drinks, caffeine is only half the story: a 355 ml can of cola delivers around 40 mg of caffeine plus about 35 g of sugar, which uses up the stricter WHO daily target for free sugars completely. How much sugar fits your calorie needs is what the sugar intake calculator works out for you, and the calorie calculator gives you your calorie needs themselves.