Black tea vs Yerba mate: caffeine compared
Yerba mate (8 oz) has 78 mg of caffeine, 31 mg more than Black tea (8 oz, 47 mg) — 1.7× as much per serving. Per fluid ounce, Yerba mate is the stronger drink: 9.8 mg/oz versus 5.9 mg/oz.
| Black tea | Yerba mate | |
|---|---|---|
| Serving | 8 oz | 8 oz |
| Caffeine per serving | 47 mg | 78 mg |
| Per fl oz | 5.9 mg | 9.8 mg |
| Share of 400 mg/day | 12% | 20% |
| Servings to reach 400 mg | 8.5 | 5.1 |
| Hours until under 50 mg | already under | 3.2 h |
| Last one for an 11 PM bedtime · standard (50 mg) | 11:00 PM | 7:48 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 6:27 PM | 2:48 PM |
| Share of the 200 mg pregnancy limit | 24% | 39% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, Black tea or Yerba mate?
Yerba mate (8 oz) has about 78 mg versus 47 mg in Black tea (8 oz): 31 mg more, or 1.7× as much.
Which is stronger per ounce, Black tea or Yerba mate?
Yerba mate: about 9.8 mg per fl oz versus 5.9 mg for Black tea. Serving size decides the total you actually drink.
How many Black tea servings equal one Yerba mate?
About 1.7 servings of Black tea (8 oz) match the caffeine in one Yerba mate (8 oz).
When should I stop drinking Black tea or Yerba mate before bed?
For an 11 PM bedtime with a 50 mg limit and a 5-hour half-life: last Black tea by 11:00 PM, last Yerba mate by 7:48 PM. Half-life varies from about 1.5 to 9.5 hours between people.
Method
Caffeine per labeled serving, from the same drink table every calculator here uses (FDA/USDA reference amounts and manufacturer labels; see caffeine content of every drink). Brewed drinks vary batch to batch, so read these as typical values. Decay uses a 5-hour average half-life with a 45-minute absorption ramp; cutoff = bedtime − 5 h × log₂(dose ÷ limit). Percentages use the FDA's 400 mg/day figure for healthy adults and the 200 mg/day limit ACOG gives for pregnancy.
Source — Black tea: USDA FoodData Central (SR Legacy 173227), checked 2026-10-13. 20 mg per 100 g × 237 g.
Source — Yerba mate: CSPI caffeine chart (yerba mate, most brands), checked 2026-10-13. 40–80 mg per 6 oz, i.e. 53–107 mg per 8 oz; 78 mg sits inside that range. Published range 53–107 mg.