Free tool · Sleep
Daily caffeine calculator: how much is too much
Short answer
For most healthy adults, up to 400 mg of caffeine a day is not generally associated with negative effects, according to the FDA, and EFSA reached the same figure. In pregnancy EFSA's limit is 200 mg. Strength varies a lot: the FDA puts 12 fl oz of brewed coffee at 113–247 mg, so two large coffees can be anywhere from 226 to 494 mg.
Last reviewed 27 October 20262 published sourcesNot medical advice
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The limits
The FDA cites 400 mg a day as an amount not generally associated with negative effects in most adults, and notes that toxic effects such as seizures can be seen after rapidly consuming around 1,200 mg (U.S. FDA).
EFSA's 2015 opinion found that for healthy adults, single doses up to 200 mg (about 3 mg/kg) and habitual intakes up to 400 mg a day raise no safety concerns, and up to 200 mg a day in pregnancy (EFSA, 2015).
| Drink | Caffeine |
|---|---|
| Brewed coffee | 113–247 mg |
| Black tea | 71 mg |
| Green tea | 37 mg |
| Caffeinated soft drink | 23–83 mg |
| Energy drink | 41–246 mg |
Timing matters as much as the total
A total under the limit can still cost you sleep if the last cup is late. Find your latest sensible coffee with the caffeine cutoff calculator, and plan your night with the sleep calculator.
Log it once, see it wear off
Reps lets you log caffeine from a Home Screen widget and shows how much is still active, with a personal cutoff time tied to your sleep.
Free to download · iPhone, iPad and Apple Watch
Common questions
How much caffeine is safe per day?
The FDA cites 400 mg a day as an amount not generally associated with negative effects for most adults, and EFSA concluded habitual intakes up to 400 mg a day raise no safety concerns for healthy adults outside pregnancy. Some people are more sensitive and feel effects at much less.
How much caffeine can I have when pregnant?
EFSA found intakes up to 200 mg a day from all sources do not raise safety concerns for the fetus. The FDA advises talking to your health care provider if you are pregnant, trying to become pregnant or breastfeeding.
How much caffeine is in a cup of coffee?
It depends on the beans, the brew and the cup size. The FDA gives 113–247 mg for 12 fl oz of regular brewed coffee, compared with 71 mg for black tea and 37 mg for green tea in the same volume.
Sources
Figures on this page were checked against these publications on 27 October 2026.
- U.S. Food and Drug Administration. Spilling the Beans: How Much Caffeine is Too Much? Consumer Update (content current as of 28 August 2024). www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the safety of caffeine. EFSA Journal. 2015;13(5):4102. doi.org/10.2903/j.efsa.2015.4102
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