Caffeine Calculator
Track caffeine in your system and find the optimal time for sleep.
0 mg
mg total from 1 coffee(s)
Peak Time
-
Safe to Sleep
-
Level
Low
Caffeine Levels Over Time
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.
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
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.
About the Caffeine Calculator
This caffeine calculator estimates health and fitness metrics from your personal inputs. Track caffeine levels and when it leaves your system.
Use for personal wellness tracking and education. Consult a healthcare provider for medical advice.
Adjust the inputs above to model your specific scenario with the Caffeine Calculator.
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