Caffeine Metabolism Tracker
Predict caffeine levels in your system to optimize focus and sleep
What is Caffeine Metabolism
Track how much caffeine is still in your system: log each drink (espresso, latte, americano, tea, energy drink — or enter milligrams by hand) with the time you had it, and the tool plots a residual-caffeine curve on a ~5–6 hour half-life model, flagging your estimated peak and a "under 50 mg by bedtime" warning. Sign-in required.
How to use Caffeine Metabolism
- Add a record each time you have a caffeinated drink (type, time, amount)
- Watch the live residual-caffeine curve update
- Use the bedtime projection to decide when to stop for the day
Frequently asked questions
How long is caffeine's half-life?
About 5 hours in a healthy adult on average — the real range is roughly 2–10 hours and shifts with genetics, smoking, pregnancy and oral contraceptives. The curve is an average-case estimate.
Will a 3 pm coffee affect my sleep?
Possibly — on the 5-hour model, a 200 mg dose at 3 pm still leaves about 100 mg in your system at 10 pm. Sensitive sleepers usually do better cutting off around noon.
Is this medical advice?
No — the model uses population-average metabolism and is meant for planning your day, not diagnosing anything. Palpitations or chronic insomnia deserve a doctor, not a chart.
Is Caffeine Metabolism free?
Caffeine Metabolism is completely free — open the page and use every feature with no hidden charges.
Do I need to download or install Caffeine Metabolism?
No download or installation is needed. It is an online tool that runs in the browser on your phone, tablet and computer.
Do I need an account to use Caffeine Metabolism?
No. Use the tool right away — no account or sign-in required.
Does Caffeine Metabolism work on mobile?
Yes. The page is fully responsive and works on phones, tablets and desktop browsers.