Caffeine Calculator
Estimate caffeine left at bedtime from your drinks and a half-life model, plus a last-coffee cutoff. Schedule helper only — not medical advice.
Frequently asked questions
How is this estimated?
Caffeine falls with a simple half-life model (about 5–7 hours by sensitivity). The last-coffee cutoff models a typical 95 mg coffee.
Is this medical advice?
No. It is a schedule helper only — not a diagnosis, treatment, or medical advice.
Is my data sent to a server?
No. This calculator runs entirely in your browser. Nothing you type is uploaded.