How Much Coffee Is Too Much

The FDA guideline is 400mg of caffeine per day for healthy adults — approximately 4 standard cups of drip coffee, 3 cold brews, or 6 espresso shots. This is a population-level recommendation, not a personal prescription.

The Signals

Your body tells you when you have had too much: jitteriness, elevated heart rate, anxiety-like symptoms, digestive distress, and sleep disruption. Caffeine's half-life is 5 to 6 hours. A cup at 3 PM means half the caffeine is still in your blood at 9 PM.

The Practical Framework

Rather than tracking milligrams, drink until you feel good and stop before you feel bad. The space between "alert and focused" and "jittery and anxious" is your window. For most people, that is 2 to 4 cups per day. If you want to drink less, reduce gradually — cut one half-cup per day over a week. Switch your last cup to decaf. Replace one coffee with a matcha latte. 400mg is the guideline. Your body is the authority. Listen to it.

Keep reading: How Much Caffeine Is in Coffee, Coffee and Sleep, Coffee and Anxiety.