Caffeine Half-Life Calculator
Caffeine Dose (mg)
Please enter a valid positive dose.
Half-Life (hours)
Please enter a valid positive half-life.
Hours Since Consumption
Please enter a valid non-negative number of hours.
Calculate
Results
200.00 mg
Estimated caffeine remaining in your system.
Time to elimination (99%):
33.2
hours
Formula:
Remaining = Dose × 0.5
(hours / half-life)
. Elimination time (99%) = half-life × log
2
(100).