Caffeine Half-Life Tracker
Track your caffeine intake and see current blood levels for better sleep quality.
Caffeine Half-Life Tracker
Track your caffeine intake and see current blood levels to manage consumption for better sleep
Add Caffeine Intake
Select a common caffeine source to automatically fill in the caffeine amount
Enter the time when you consumed the caffeine
Enter the source or type of caffeinated beverage
Intake History (0)
No caffeine intakes recorded yet.
Add your first intake above to start tracking.
Formula
C(t) = C₀ × (1/2)^(t/5h)Caffeine follows exponential decay with a 5-hour half-life. After 5 hours, 50% remains; after 10 hours, 25% remains.
How to Use
- 1Add your drinks — Enter each caffeinated drink with its time of consumption and caffeine amount.
- 2View current level — See your estimated current caffeine level based on 5-hour half-life.
- 3Check timeline — View how your caffeine levels will decay over the next hours.
- 4Read recommendations — Get personalized sleep recommendations based on your current level.
- 5Plan your intake — Use the tracker to optimize coffee consumption for better sleep.
Frequently Asked Questions
What is caffeine half-life?
Caffeine half-life is the time it takes for your body to eliminate half of the caffeine. The average is approximately 5 hours. After 5 hours, 50% remains; after 10 hours, 25%; after 15 hours, 12.5%.
How much caffeine is safe before sleep?
For optimal sleep, caffeine levels should be below 50mg. Levels between 50-100mg may slightly affect sleep, while above 100mg can significantly impact sleep quality.
How does this caffeine tracker work?
The tracker uses the exponential decay formula C(t) = C₀ × (1/2)^(t/5h) to calculate remaining caffeine from each intake, then sums them for your current level.
How much caffeine is in common drinks?
Espresso (single): 64mg, Espresso (double): 128mg, Pour Over: 95mg, Drip Coffee: 95mg, French Press: 107mg, Cold Brew: 200mg, Energy Drink: 80mg, Green Tea: 28mg.
Does caffeine half-life vary between people?
Yes, half-life can range from 3 to 7 hours depending on genetics, age, liver function, pregnancy, and medications. This calculator uses the average 5-hour half-life.