Your last coffee.
Stop six hours before bed. Sleep deeper.
Bedtime
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Last caffeine by
4:30 PM
About 44% of a coffee is still in your system at bedtime.
Questions
How many hours before bed should I stop caffeine?
At least 6 hours. A 2013 study found 400 mg of caffeine even 6 hours before bed cut sleep by over an hour, so caffeine-sensitive people may need 8–10 hours.
What is the half-life of caffeine?
About 5 hours on average in healthy adults, but it ranges roughly 1.5–9.5 hours depending on genetics, pregnancy, smoking, and some medications. After 5 hours about half the caffeine is still in your system.
Is 2 PM too late for coffee?
With a 10:30 PM bedtime and a 6-hour buffer, your cutoff is 4:30 PM, so 2 PM is usually fine. If you go to bed at 9 PM or are caffeine-sensitive, 2 PM may be too late.
Does decaf have caffeine?
A little — typically around 2–15 mg per cup, far less than regular coffee's ~95 mg.