Caffeine Tracker

Click a time segment to add a coffee. Click a red layer to remove it. Hover cursor or drag finger along outer rim for stats.
Figures are approximate. Settings at bottom.

0 Cups

Settings & Information

Personalization options (saves a 7-day browser cookie).

Individual half-life: hours Concentration: mg/cup

Half-Life & Metabolism

Caffeine is steadily metabolized by the liver enzyme CYP1A2, but half-lives vary hugely.

Baseline adult~4–5 h

Hyperactive CYP1A2~2–3 h

Heavy smoker~3 h

Smoked meat~3-4 h

Antibiotics~5–8 h

Obesity~5–7 h

Underactive CYP1A2~6–10 h

Oral contraceptives~10–11 h

Pregnancy~4–15 h

Fluvoxamine (SSRI)~31 h

Methoxsalen (skin med)~50 h

Liver disease~6–180 h

Grzegorzewski, J., Bartsch, F., Köller, A., & König, M. (2022). Pharmacokinetics of caffeine: a systematic analysis of reported data for application in metabolic phenotyping and liver function testing. Frontiers in pharmacology, 12, 752826.

Beverage Concentrations

Filtered coffee, large cup (250ml)~120 mg

Chocolate (50g)~10 mg

Cola can (355ml)~40 mg

Black tea (300ml cup)~50 mg

Espresso (single)~80 mg

Yerba Mate (mug)~50-150 mg

Energy drink (can)~150 mg

Cold brew (glass)~190 mg

Coffee, Finnish mug~240 mg

Starbucks Venti~400 mg

Concentration varies by brand and preparation method. Caffeine Informer provides more examples.

About This App

This software is provided freely under the MIT License and runs completely in your browser.

Code hosted on GitHub. No individual data is collected, though I use Counter.dev to count anonymous visitors.

Read my blog post for more background or to leave a comment!

I hope you benefit,
/Juhani