Black tea vs Green tea: which has more caffeine?
A cup of black tea has on average about 1.6× more caffeine than green tea.
Per 100 ml: black tea has about 1.6× more caffeine than green tea.
The ranges overlap, so in a particular cup the difference can go the other way.
| Black tea | Green tea | |
|---|---|---|
| Caffeine per cup | 14–48 mg | 11–29 mg |
| Volume | 237 ml | 237 ml |
| mg / 100 ml (average) | 13.1 | 8.4 |
| Cups to reach 400 mg a day (adult) | 12 | 20 |
Frequently asked questions
Which has more caffeine: Black tea or Green tea?
A cup of black tea has on average about 1.6× more caffeine than green tea. The ranges overlap, so in a particular cup the difference can go the other way.
How many cups of green tea equal one cup of black tea?
Using average values, one cup of black tea (31 mg) equals about 1.6 cups of green tea (20 mg). This is a guide, since both drinks vary by batch and preparation.
Which is better in the evening?
Green tea has less caffeine per cup (about 20 mg versus about 31 mg for black tea). After 6 hours roughly half to a third of what you drank remains, but sensitivity varies a lot.
Try it
Sources and method
- 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)
- EUFIC: EFSA opinion on the safety of caffeine (2015)
Data checked 2026-10-24. Ranges are shown because studies report different numbers. General information, not medical advice.