Caffeine Half-Life Calculator
Calculate how long caffeine stays in your system and its effect on sleep based on consumption time.
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Caffeine Half-Life
Caffeine has an average half-life of about 5 hours in healthy adults, meaning half the caffeine is eliminated every 5 hours. Factors like genetics, age, medications, and liver function can affect this (range: 3-7 hours). Sleep experts recommend keeping caffeine below 50 mg at bedtime, which typically means no coffee after early afternoon.