Green tea vs Oolong tea: which has more caffeine?
Green tea and oolong tea have similar caffeine per cup (a difference of under 20%).
Per 100 ml the caffeine is similar.
| Green tea | Oolong tea | |
|---|---|---|
| Caffeine per cup | 11–29 mg | 4–29 mg |
| Volume | 237 ml | 237 ml |
| mg / 100 ml (average) | 8.4 | 7.2 |
| Cups to reach 400 mg a day (adult) | 20 | more than 20 |
Frequently asked questions
Which has more caffeine: Green tea or Oolong tea?
Green tea and oolong tea have similar caffeine per cup (a difference of under 20%).
How many cups of oolong tea equal one cup of green tea?
Using average values, one cup of green tea (20 mg) equals about 1.2 cups of oolong tea (17 mg). This is a guide, since both drinks vary by batch and preparation.
Which is better in the evening?
Oolong tea has less caffeine per cup (about 17 mg versus about 20 mg for green 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
- 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.