Caffeine Calculator
Search thousands of drink variations, track what you actually consumed, view your daily and weekly history, and estimate how long today's caffeine may remain in your system.
Daily Caffeine Calculator
Search for a drink and mark it as consumed. History only records drinks you explicitly add.
Caffeine History
Only drinks you explicitly marked as consumed are saved.
Caffeine History
Linear trend based on your saved entries.
Your history is stored locally in this browser.
Caffeine Statistics
See your intake by day, week, month or year.
Consumed vs Absorbed vs Remaining
Top Caffeine Sources
Absorbed Caffeine by Product
Caffeine by Category
Detailed Period Data
| Period | Consumed | Absorbed | Remaining | Drinks |
|---|
How Long Is Caffeine in Your System?
This calculator automatically uses the drinks you marked as Consumed today and estimates how much caffeine is still in your system right now.
Caffeine Remaining Over Time
The line starts with the estimated amount still in your system right now — not with the original amount you consumed.
Every point is calculated from the caffeine entries saved in your History that may still be contributing caffeine now.
Today’s caffeine sources
This is a simplified, illustrative model. It is not a medical measurement or a personalized pharmacokinetic calculation.
Caffeine by Drink
Popular drinks are shown first. Click the button to reveal the complete database.
| Drink | Serving | Estimated caffeine |
|---|
Frequently Asked Questions
Common questions about using the calculator.
How does Caffeine History work?
Only drinks that you explicitly mark as Consumed are added to your local history.
Can I record absorbed caffeine?
Absorbed caffeine is shown as a user estimate when that value is stored with an entry. It is not a medical measurement.
What does Remaining mean?
Remaining is simply Caffeine Consumed minus the absorbed value you entered. It is not a measurement of caffeine remaining in your body.
Where is my history stored?
Your history is stored in localStorage in your browser.
How accurate is the caffeine database?
Values are estimates and can vary by product, flavour, serving size, market and preparation. Check the product label for the most accurate value.
Privacy
This standalone version stores your caffeine history locally in your browser. No caffeine history is uploaded to a server by this page.
Disclaimer
This site provides general informational estimates. Absorbed caffeine values are user-entered estimates and not medical measurements. The personalized time-in-system estimate is a simplified model and not medical advice.