Live tool/tool/caffeine-half-life-calculator

Caffeine Half-Life Calculator

Estimate how much caffeine remains in your system after a given number of hours and a chosen half-life assumption.

HealthReferenceLifestyle

Caffeine intake

Hours since intake

Half-life

Remaining caffeine

79 mg

Equivalent coffees

0.8

Cleared

161 mg

Half-life used

5 hr

Reminder

Metabolism varies a lot across people, medications, and pregnancy. This is only a rough model.