Oolong Tea contains 37 mg of caffeine per 8 oz cup (237 ml / 8 oz). That is about 39% of the caffeine in a typical 8 oz cup of brewed coffee (about 95 mg). Concentration: 15.6 mg per 100 ml.
Track your caffeine with Unbuzz, free on the App Store.
Oolong Tea Caffeine Content by Serving
Figures are for Oolong tea (brewed).
| Serving | Volume | Caffeine | Per 100 ml | Level |
|---|---|---|---|---|
| 8 oz cup | 237 ml / 8 oz | 37 mg | 15.6 mg | Low |
Source: caffeine figures from Caffeine Informer, accessed 2026-06-11. Values can vary by batch, location, and preparation; check the label or the source for the latest figures.
How Oolong Tea Compares to Coffee
At 37 mg per 8 oz cup, Oolong Tea delivers about 39% of the caffeine in a typical 8 oz cup of brewed coffee (about 95 mg). For a wider comparison across drinks, try the caffeine comparison tool or browse the full caffeine database.
When to Stop Drinking Oolong Tea Before Bed
An 8 oz cup of Oolong Tea (37 mg) stays under the 50 mg sleep-ready threshold from the first sip, so a normal serving is unlikely to delay sleep on its own. Multiple servings stack, though: caffeine's median half-life is about 5 hours, so a second or third serving in the afternoon can still add up past 50 mg by bedtime.
The Oolong Tea sleep cutoff page has last-call times for four bedtimes, and the caffeine half-life calculator personalizes the curve to your metabolism.
