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Caffeine Cutoff Calculator
The 2pm coffee that used to be fine can be exactly what's wrecking tonight's sleep now. This gives you an actual cutoff instead of a guess.
Ideally your last cup by11:30 AM
Absolute latest6:00 AM
Based on typical caffeine half-life for your sensitivity level. Perimenopause can make sleep more sensitive to caffeine than it used to be, even if your habits haven't changed.
How to use this
- 1Enter your usual bedtime.
- 2Pick how caffeine tends to affect you.
- 3Use the earlier time as your real target, and the later one as a hard stop.
Work Sharp's sleep card includes this kind of timing guidance as part of your personal plan — set once and applied every day.
See the full protocol →