Observed arrival · 2026-09-28
Caffeine vs Water maps a coffee to bedtime
A caffeine-and-hydration planner for iPhone and Apple Watch, with a homepage calculator that estimates how much caffeine from a drink remains at bedtime.
- For
- Coffee drinkers planning around bedtime
- Worth noticing
- The calculator offers six caffeine-clearance presets, including smoking, oral contraceptive use, and pregnancy.
Field notes
The page’s calculator exposes its assumptions rather than returning a bare number: drink dose, timing, and a selected caffeine-processing preset feed an estimate of active caffeine at bedtime. It lists a typical 5.5-hour half-life alongside alternatives, and cautions that the result is general wellness information, not medical advice. The app description says it would also pair coffee with water tracking and use Apple Health for sleep comparisons; the app itself is marked as coming soon.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
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