Caffeine calculator
See how much caffeine you get from your cup of tea. No sign-up needed.
Tea
Tea amount
Water
Steeping time
Caffeine in your cup
13–45 mg
≈ 5.2–18.0 mg / 100 mlA range is shown because studies report different numbers: caffeine depends on the tea, the batch and how it is prepared. General information, not medical advice.
Sources
- Ayakdaş & Ağagündüz, Foods 2025;14(13):2313 (68 tea samples)
- Mayo Clinic: Caffeine content for coffee, tea, soda and more
- Caffeine Informer: brewed tea (lab averages and brew-time tests)
- Markowicz Bastos et al., Acta Farm. Bonaerense 2005;24(1):91–95 (yerba mate)
- Caffeine Informer: yerba mate (producer data)
- Medical News Today: matcha caffeine (19–44 mg/g, citing Kochman et al. 2020)
- EUFIC: EFSA opinion on the safety of caffeine (2015)
- Wikipedia: Rooibos
- Caffeine Informer: Herbal tea caffeine content
- Wikipedia: Herbal tea
- FSANZ P1056: caffeine safety assessment (half-life, EFSA values)
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