Caffeine Half-Life Visualizer

Your caffeine through the day, one dose per line as HH:MM mg (24-hour time). The curve adds every dose together.

Rough amounts: espresso 60–90 mg, filter coffee 90–140 mg, tea 40–60 mg, energy drink 80–160 mg.

How many hours it takes your body to clear half the caffeine. A longer half-life leaves more in your system at night.

Typical adults are 3–7 h; pregnancy and some medications lengthen it, smoking shortens it.

When you plan to sleep, in 24-hour HH:MM form. The tool reads off how much caffeine is left at this time.

The amount below which you consider caffeine unlikely to disturb sleep. The chart marks when you drop under it.

50 mg is roughly half an espresso, but sensitivity varies a lot.