How Much Caffeine Is Safe Per Day? The Research-Based Limit
Up to 400mg is safe for most adults. Here is what that looks like in actual drinks.
The FDA and European Food Safety Authority agree: up to 400mg of caffeine per day is safe for healthy adults. That is roughly: 4 cups of brewed coffee (95mg each), 5 shots of espresso (63mg each), 8 cups of green tea (47mg each), or 10 cans of cola (34mg each). Pregnant women should limit to 200mg/day. Children and teens: limited data, but the American Academy of Pediatrics recommends avoiding caffeine entirely under age 12 and limiting to 100mg for teens.
Caffeine Content by Drink
Brewed coffee (8 oz): 80-100mg. Cold brew (12 oz): 150-240mg (much higher than regular). Espresso shot: 63mg. Latte/cappuccino: 63-126mg (1-2 shots). Black tea (8 oz): 47mg. Green tea (8 oz): 28mg. Cola (12 oz): 34mg. Energy drink (16 oz): 150-300mg. Pre-workout supplement: 150-400mg per serving. Caffeine pill: 100-200mg.
Signs You Are Having Too Much
Anxiety and jitteriness. Insomnia (caffeine half-life is 5-6 hours — a 2 PM coffee is half-strength at 8 PM). Rapid heart rate. Digestive issues. Headaches (often from withdrawal, not excess). If you experience these symptoms, reduce intake gradually — cutting caffeine cold turkey causes withdrawal headaches for 2-9 days.