Caffeine Intake Calculator
Pick what you drank today. We'll show your total caffeine and whether you're within the safe limit (400 mg/day for healthy adults).
1 serving = 8 fl oz (240 ml)
1 serving = 8 fl oz (240 ml)
You can still have about 1.7 more cup(s) of brewed coffee before hitting the limit.
Guidance for healthy adults
FDA guidance: up to 400 mg per day (about 4 cups of brewed coffee) is generally not associated with negative health effects in healthy adults.
How to use the caffeine intake calculator
Start by picking your demographic from the dropdown — the safe daily limit changes based on whether you are a healthy adult (400 mg/day), pregnant or breastfeeding (200 mg/day), an adolescent aged 12–18 (100 mg/day), or a child under 12 (0 mg/day). Then add each beverage you consumed today: choose from the 36+ drinks in our database, enter how many servings you had, and the calculator sums up your total caffeine intake in milligrams and shows your status (within limit, close to limit, or over limit).
The progress bar shows how close you are to the safe limit for your group, and the headroom calculation tells you exactly how much more caffeine you could safely consume — for example, "about 1.1 cups of brewed coffee." If you go over, the badge turns red and you'll see how many mg you exceeded the limit by.
Each beverage's caffeine value comes from the USDA FoodData Central database or manufacturer-published nutrition labels. Actual caffeine content can vary by 20% or more depending on brew strength, brand, and serving size, so treat totals as estimates. For example, a Starbucks Grande Pike Place has 310 mg of caffeine — significantly more than a generic 8 oz brewed coffee at 95 mg — even though both are "a cup of coffee."
What counts as a "serving" of caffeine?
Caffeine servings vary widely by drink type. A standard serving of brewed coffee (8 fl oz / 240 ml) has about 95 mg of caffeine. A single shot of espresso (1 fl oz / 30 ml) has 63 mg. A 12 oz can of Coca-Cola has 34 mg, while a 16 oz Monster Energy has 160 mg. The calculator lets you specify the number of servings — so if you drank a 16 oz travel mug of coffee, that's 2 servings of 8 oz brewed coffee, or about 190 mg of caffeine.
Why the 400 mg limit?
The FDA's 400 mg/day guidance for healthy adults reflects decades of research showing that at this level, caffeine is not associated with negative cardiovascular, neurological, or reproductive health effects in most adults. Above 400 mg/day, some people experience insomnia, jitteriness, anxiety, elevated blood pressure, digestive upset, or rapid heartbeat. Individual tolerance varies significantly based on genetics (the CYP1A2 gene in particular), body weight, and regular usage. If you're sensitive to caffeine, your personal limit may be meaningfully lower.