Caffeine Calculator
Track caffeine in your system and find the optimal time for sleep.
How many cups/cans did you consume?
ml
Size of each serving in milliliters.
Current Level
0 mg
mg total from 1 coffee(s)
Peak
Peak Time
-
Sleep
Safe to Sleep
-
Status
Level
Low
Caffeine Levels Over Time
Documentation
How Caffeine Works in Your Body
Caffeine has a half-life of approximately 5-6 hours in most adults. This means that if you consume 200mg of caffeine, after 5 hours you will still have about 100mg in your system.
💡 Pro Tip
The FDA recommends a maximum of 400mg of caffeine per day for healthy adults. Stop caffeine intake at least 6 hours before bedtime for optimal sleep quality.
The Half-Life Formula
C(t) = C₀ × (0.5)^(t/5)
Where Câ‚€ = initial caffeine, t = hours elapsed, 5 = half-life in hours
Last Updated: February 2026
Disclaimer: Individual caffeine metabolism varies based on genetics, age, weight, medications, and other factors. This calculator provides estimates based on average values.
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