Health & Fitness CalculatorsPrivate by design
Caffeine Half-Life Calculator
Enter your caffeine dose, hours elapsed, and half-life to estimate how much caffeine remains in your system.
How to use this tool
- 1Enter the caffeine dose consumed.
- 2Enter hours elapsed since consuming it.
- 3See the estimated remaining caffeine.
Frequently asked questions
Why does caffeine half-life vary so much between people?+
Genetics (especially the CYP1A2 gene), pregnancy, liver function, smoking status, and certain medications can all significantly speed up or slow down caffeine metabolism.
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