A small plan, grounded in research
This model adds the estimated caffeine remaining from each drink using exponential decay. It assumes the full amount is available at the drink time and does not model absorption. Drink sizes, caffeine content and clearance all vary. The result is an illustration, not a measurement.
Caffeine can interfere with sleep. A low estimate does not mean it is safe to drink or that sleep will be unaffected. This adult tool gives no personal safe dose or medical advice. For pregnancy or medication questions, ask a professional.
A few useful answers
Why show more than one estimate?
Half-life varies substantially between people and circumstances. EFSA describes a wider range than the illustrative band shown here. The assumptions in this tool illustrate uncertainty; they do not cover every person.
Can this tell me what to drink before an exam?
No. It does not predict exam performance, alertness or an individual safe dose. It helps adults explore how the timing of drinks could affect caffeine remaining at bedtime.
What if my drink is stronger?
Use the label or a measured amount if available and edit the milligrams. The common-drink values are approximate examples from EFSA, not fixed values for every serving.
