Caffeine Half-Life Tracker
Log your daily caffeine intake, estimate remaining caffeine using half-life, and view the combined metabolism curve for multiple drinks.
What does caffeine half-life mean?
Half-life is the time for caffeine amount to halve during elimination. The default scenario is 5 hours; adjust it to compare estimated remaining amounts.
How are multiple drinks calculated?
Each dose is calculated from its own intake time with absorption and elimination. The estimated amounts are then added together.
Do yesterday’s drinks count?
Yes. Remaining caffeine and the chart include saved entries from the previous 7 days. Today’s intake includes today only; unrecorded drinks cannot be estimated.
Is mg a blood concentration?
No. It is an estimated caffeine amount, not blood concentration or a prediction of when you can sleep. 50mg and 10mg are chart references only.
Where are records saved?
Guest entries stay in this browser and are lost if browser storage is cleared. Signed-in intake logs sync to your account. Custom half-life scenarios stay in this browser.