Daily Caffeine Stack
Add up everything you drink today
Stack energy drinks (and any other caffeine) by time. See your day total, how it compares to a 400 mg reference, and an estimate of caffeine remaining as the day goes on.
Quick start
Jump in with a sample day — edit times and amounts after.
Today’s stack
Add a drink to start building your day.
Default 400 mg is a common adult reference — set your own target if you prefer.
We’ll say whether estimated remaining at bedtime is under this amount.
Advanced settings
Default 5-hour half-life is a common average, not a personal measurement.
Total caffeine today
0 mg
vs 400 mg daily target
- Drinks logged
- 0
- Estimated remaining now
- ~0 mg
- Sugar (known)
- —
- Calories (known)
- —
- Estimated remaining at bedtime
- Bedtime clear check
A chart of estimated caffeine remaining as drinks are added through the day. Markers show each drink; a solid line marks now; a dashed line marks bedtime when set.
Hour-by-hour estimates
| Time | Estimated remaining |
|---|
Totals sum what you add for the day. Remaining estimates use a caffeine half-life model and are for informational purposes only — not a blood measurement or medical advice. The 400 mg figure is a commonly cited adult daily reference, not a personal medical limit.
How the daily caffeine stack works
What is a daily caffeine stack?
A daily caffeine stack is everything caffeinated you drink in one day — energy drinks, coffee, tea, or anything else you enter. This tool adds those amounts so you can see a running total and an estimate of how much may still be in your system as the day goes on.
How is this different from the half-life calculator?
The half-life calculator models one dose at a time. The daily stack lets you add several drinks with different times, totals caffeine (and sugar/calories when known from the database), and estimates remaining caffeine from the whole day.
What does the 400 mg reference mean?
400 mg is a commonly cited reference amount for caffeine from all sources for healthy adults in a day. It is not a personal medical limit. Pregnancy, sensitivity, medications, and other factors can change what is appropriate for you.
How does the remaining-caffeine estimate work?
Each drink is treated as its own dose that decays with a default 5-hour half-life. At any time of day, the tool adds the estimated remainder from every drink you have already logged. Future drinks in your stack count toward the day total but not toward “remaining now” until that time passes.
Can I use verified energy drinks from Energeia?
Yes. Search for a drink to fill in a verified caffeine amount from the Energeia database. Half-can and custom-oz servings scale sugar and calories when those values are on file. You can also type milligrams manually for coffee or drinks not in the catalog.
Is this the same as the Energeia Tracker app?
No. This page is a quick browser calculator. Energeia Tracker on iPhone can scan cans, save a history, and export a CSV you can explore in Log Insights. Use the stack tool for a fast day estimate without installing anything.
Related tools
Modeling one drink? Open the half-life calculator . Already tracking in the app? Visualize your CSV export .