Find a drink, see its caffeine, and tap Add to build your day. The total is measured against the FDA’s 400 mg for healthy adults — or ACOG’s 200 mg in pregnancy — with every number’s source named.
Your caffeine today
270 mg 68% of the FDA’s 400 mg
This is not medical advice and it does not diagnose anything. People differ a lot in how caffeine affects them; if you are pregnant or breastfeeding, have a heart condition or anxiety, or take medication — especially antidepressants, blood thinners or blood-pressure medicine — ask your doctor or pharmacist what is right for you.
How much caffeine is too much? For healthy adults the FDA cites 400 mg a day — about four 8 fl oz cups of brewed coffee at USDA’s 95 mg a cup. In pregnancy ACOG’s line is under 200 mg. This chart lists the caffeine in common drinks, each figure from USDA, the FDA or the brand itself, and adds up your day against the line that applies to you.
How to use it
Search for a drink or scroll the list, and tap Add for each one you have in a day. Tap + and − to change how many. Pick whose limit applies — adult, pregnant or under 18. Where the only published figure is a range (the FDA’s ranges for coffee-shop coffee, sodas and energy drinks), the range is carried into your total instead of being averaged away, so the page can tell you when you “could be over”.
The lines, in their sources’ own words
- Adults: 400 mg a day. “For most adults, the FDA has cited 400 milligrams a day — that’s about two to three 12-fluid-ounce cups of coffee — as an amount not generally associated with negative effects.”
- Pregnancy: under 200 mg a day. ACOG: “Moderate caffeine consumption (less than 200 mg per day) does not appear to be a major contributing factor in miscarriage or preterm birth.” The FDA adds that if you are pregnant, trying to be or breastfeeding, talk to your health care provider about whether to limit caffeine.
- Under 18: no published number. No US agency publishes a daily milligram figure for teens, so this chart does not print one. What the FDA does say: “Medical experts advise against energy drinks for children and teens because of the levels of sugar and caffeine, according to the American Academy of Pediatrics,” and the Dietary Guidelines say caffeinated drinks should be avoided under age 2.
Caffeine in common drinks
| Drink | Serving | Caffeine | Source |
|---|---|---|---|
| Brewed coffee | 8 fl oz (237 ml) | 95 mg | USDA FoodData Central |
| Espresso | single shot, 1 fl oz | 63 mg | USDA FoodData Central |
| Instant coffee | 8 fl oz (237 ml) | 62 mg | USDA FoodData Central |
| Decaf coffee | 8 fl oz (237 ml) | 2 mg | USDA FoodData Central |
| Brewed coffee — the FDA’s range | 12 fl oz | 113–247 mg | the FDA |
| Black tea, brewed | 8 fl oz (237 ml) | 47 mg | USDA FoodData Central |
| Green tea, brewed | 8 fl oz (237 ml) | 28 mg | USDA FoodData Central |
| Coca-Cola | 12 fl oz can | 34 mg | The Coca-Cola Company |
| Diet Coke | 12 fl oz can | 46 mg | The Coca-Cola Company |
| Cola, regular | 12 fl oz (355 ml) | 33 mg | USDA FoodData Central |
| Pepper-type soda | 12 fl oz (355 ml) | 37 mg | USDA FoodData Central |
| Caffeinated soft drink — the FDA’s range | 12 fl oz | 23–83 mg | the FDA |
| Red Bull Energy Drink | 8.4 fl oz can | 80 mg | Red Bull |
| Monster Energy (USDA’s lab figure) | 16 fl oz can | 158 mg | USDA FoodData Central |
| Energy drink — the FDA’s range | 16 fl oz | 54–328 mg | the FDA |
| Caffeine tablet (alertness aid) | 200 mg tablet | 200 mg | the FDA’s OTC monograph (21 CFR 340.50) |
| Pre-workout, standard serve | 1 serve | 217.5 mg | Gardiner et al. (2023) |
| Dark chocolate, 70–85% cacao | 1 oz (28 g) | 23 mg | USDA FoodData Central |
| Dark chocolate, 45–59% cacao | 1 oz (28 g) | 12 mg | USDA FoodData Central |
| Hot cocoa, homemade | 1 cup (250 g) | 5 mg | USDA FoodData Central |
USDA rows are USDA’s caffeine per 100 g times USDA’s own weight for that serving; bigger sizes in the calculator scale the same way. Red Bull’s and Coca-Cola’s figures are from their own sites. The pre-workout figure is the “typical caffeine content” a 2023 sleep meta-analysis used — pre-workouts vary widely, so use your tub’s label.
Worked examples
- Two coffees and a Red Bull. 2 × 95 mg + 80 mg = 270 mg: 68% of the FDA’s 400 mg, or 2.8 cups of brewed coffee.
- Two 12 fl oz coffee-shop coffees. The FDA’s range for one is 113–247 mg, so two are 226–494 mg — the chart says this could be over 400 mg, because it depends on how strong the brew is.
- Pregnant, one coffee and one 16 fl oz energy drink. 95 mg plus the FDA’s 54–328 mg range is 149–423 mg: it could be over ACOG’s 200 mg, and the only way to know is the can’s label.
- A 16 fl oz coffee and a Monster. 189 mg + 158 mg = 347 mg, under 400 mg with 53 mg to spare.
Common mistakes
- Counting “cups” instead of milligrams. A coffee-shop large is often two or more 8 fl oz cups.
- Forgetting the pre-workout and the tablets. A single serve can be half the day’s 400 mg.
- Treating 400 mg as a target. It is an amount the FDA says is not generally linked to negative effects in healthy adults — not a goal, and not a sleep rule. For sleep, the caffeine cutoff calculator shows when your last one should be.
- Assuming decaf is zero. The FDA puts it at 2–15 mg a cup.
Frequently asked questions
How much caffeine is too much?
The FDA cites 400 mg a day for most healthy adults as an amount not generally associated with negative effects. People vary widely in how sensitive they are, so less can be too much for you — and in pregnancy ACOG’s line is under 200 mg.
How much caffeine is in a cup of coffee?
USDA’s figure for an 8 fl oz cup of brewed coffee is 95 mg. The FDA’s range for a 12 fl oz regular brewed coffee is 113 to 247 mg, and an espresso shot is 63 mg in USDA’s data.
How much caffeine can I have while pregnant?
ACOG’s committee opinion says moderate caffeine — less than 200 mg a day — does not appear to be a major factor in miscarriage or preterm birth. Ask your midwife or doctor about your own limit.
How much caffeine is in tea?
USDA puts an 8 fl oz cup of brewed black tea at 47 mg and green tea at 28 mg. A strong brew or a large mug carries more.
How much caffeine is in an energy drink?
The FDA’s range is 54 to 328 mg per 16 fl oz. An 8.4 fl oz Red Bull is 80 mg on Red Bull’s own figures; USDA measured a 16 fl oz Monster at about 158 mg.
What is a lethal dose of caffeine?
The FDA’s framing: “toxic effects, like seizures, can be observed with rapid consumption of around 1,200 milligrams of caffeine, or less than 1/2 teaspoon of pure caffeine.” That is why pure powdered caffeine is dangerous. If someone has taken too much, call Poison Help at 1-800-222-1222, or 911.
How many cups of coffee is 400 mg?
About four 8 fl oz cups at USDA’s 95 mg (4.2 cups), or two to three 12 fl oz cups in the FDA’s own wording.
Read next
- Caffeine as a nootropic — the dose that helps focus, and the side effects.
- Is there caffeine in nootropics? — the stack you may be adding to your day without counting.
- Mind Lab Pro vs caffeine
- The best tea for brain fog
This is not medical advice, and nothing here diagnoses or treats anything. Talk to your doctor or pharmacist about caffeine if you are pregnant or breastfeeding, have a heart condition or anxiety, or take medication — especially antidepressants, blood thinners or blood-pressure medicine. Some links on this site are affiliate links: I buy what I review at full price, and a commission never changes a verdict.