Caffeine Half-Life Tracker
Project caffeine in your system over time from a list of doses.
0 mg
Right now
Likely OK
Sleep impact
| +hours | Remaining (mg) |
|---|---|
| +1 | 0 |
| +2 | 0 |
| +4 | 0 |
| +6 | 0 |
| +8 | 0 |
| +12 | 0 |
About the formula
Caffeine follows first-order pharmacokinetics: remaining = dose × 0.5^(hours / half-life). A typical adult half-life is ~5 hours, but ranges from 1.5 to 9.5 hours depending on liver enzymes (CYP1A2), pregnancy, smoking, and oral contraceptive use.
About this tool
Enter doses with timestamps. With an assumed half-life of ~5 hours, projects total caffeine remaining at any future hour offset. Useful for planning bedtime.