Caffeine Calculator
Caffeine has an average half-life of 5-6 hours, meaning half the caffeine from your afternoon coffee is still in your system at bedtime. Our caffeine calculator shows you exactly when caffeine from each drink clears your system, tracks your total daily intake, and tells you the latest safe time for your last caffeinated drink based on your bedtime.
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About caffeine
Caffeine has an average half-life of 5.7 hours, meaning half the caffeine you consume is still in your system nearly 6 hours later. Individual metabolism varies based on genetics, age, liver function, and medications. The FDA recommends a maximum of 400 mg of caffeine per day for most healthy adults. This tool provides estimates for informational purposes only and is not medical advice.
Better Coffee Habits
Low-caffeine alternatives, quality decaf coffee, caffeine-tracking apps, and herbal teas for the evening.
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Frequently Asked Questions
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