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What Can I Drink Now? Caffeine & Bedtime Calculator
Compare documented drinks against your chosen bedtime caffeine target, with adjustable timing and half-life. Find options and carry a serving into your tracker.
Your timing and target
The next occurrence of your bedtime is used. Choose a valid time. Half-life is an assumption, not a personal measurement.
Choose how much caffeine you want remaining from one additional serving at bedtime. This comparison excludes earlier drinks and does not define a medically safe level.
Matches within your target
Up to eight different drinks, closest to your target first. “Close to target” means within 10% below your maximum; anything exceeding it is shown separately.
No matching servings with these settings. Try a different category, earlier drinking time or a lower-caffeine drink.
How the matching works
Every serving uses the same half-life equation as the half-life calculator. Results use UK or general-reference records with unflagged evidence. Each card links to the source, serving and review date. Products can change and the model cannot predict your sleep.
Use the tracker for the combined contribution of your logged drinksCommon questions
Does 'within target' mean I will sleep well?
No. It means the mathematical estimate for this serving fits the amount you selected. Individual clearance and sleep responses vary.
Are my earlier drinks included?
No. This tool compares one new serving at a time. Your tracker calculates combined estimates from your recorded history.
What if bedtime is after midnight?
The next occurrence of your selected bedtime is used. The displayed date makes the overnight calculation explicit.