How much caffeine is too much?
The FDA cites 400 milligrams a day, about two to three 12-ounce cups of coffee, as an amount not generally associated with negative effects for most healthy adults. How caffeine affects a person varies, and a doctor can say what suits you.
Action level Worth checking
- Why you are seeing it
- It is the figure quoted in articles and on drink labels about daily caffeine.
- Why it matters
- It gives a reference point for adding up coffee, tea, soft drinks and energy drinks over a day.
- What should I do?
- Add up your own day with the Caffeine Tracker, using the amounts on your drinks.
- Remember the figure is for most healthy adults and not a personal limit.
- Ask a doctor if you are pregnant, take medicines, or notice effects at lower amounts: the figure cannot say what suits you.
- A common misunderstanding
- The 400 mg figure is not a limit set for every person: the FDA says it applies to most healthy adults.
The FDA figure
The FDA page says 400 milligrams of caffeine a day, about two to three 12-fluid-ounce cups of coffee, is an amount not generally associated with negative effects for most healthy adults. It is a general figure for most healthy adults and not a limit set for any one person.
A simple example
Adding up a day
Two 12 oz coffees at 150 mg each is 300 mg.
Add one 12 oz black tea at 71 mg and the day is 371 mg.
That is 93% of 400 mg. The real amounts in your cups may differ, so check the label if you can.
What drinks contain
| Drink | Caffeine |
|---|---|
| Caffeinated soft drink | 23 to 83 mg |
| Green tea | 37 mg |
| Black tea | 71 mg |
| Regular brewed coffee | 113 to 247 mg |
| Energy drinks | 41 to 246 mg |
Try these tools
- Caffeine TrackerList what you had and the caffeine in each to see the total for the day. Nothing is looked up or guessed.
- Caffeine Half-Life CalculatorSee how much caffeine might be left after some hours, using a half-life you choose. A model, not a measurement.