Comprehensive Guide to Tea Caffeine Levels
A standard 240 ml cup of black tea contains 47 mg of caffeine.
- Black tea (240 ml) = 47 mg caffeine; English Breakfast (240 ml) = 50 mg.
- Matcha (1 tsp in 240 ml) = 70 mg85 mg
- Green tea (240 ml) = 28 mg16 mg
- Herbal teas = 0 mg (caffeine-free); bottled iced tea (355 ml) = 45 mg
- Green tea (240 ml) = 28 mg16 mg
Caffeine levels by tea type
The dataset below lists common teas with exact caffeine amounts per serving. These are measured-per-serving values used by food databases and beverage manufacturers; small recipe or steep-time differences will move the numbers.
| Tea | Serving | Caffeine (mg) | mg/100 ml |
|---|---|---|---|
| Black tea | 240 ml | 47 mg | 19.6 mg/100ml |
| English Breakfast | 240 ml | 50 mg | 20.8 mg/100ml |
| Earl Grey | 240 ml | 47 mg | 19.6 mg/100ml |
| Green tea | 240 ml | 28 mg | 11.7 mg/100ml |
| White tea | 240 ml | 16 mg | 6.7 mg/100ml |
| Oolong tea | 240 ml | 37 mg | 15.4 mg/100ml |
| Matcha (1 tsp) | 240 ml | 70 mg | — |
| Chai latte | 240 ml | 50 mg | — |
| Yerba mate | 240 ml | 85 mg | 35.4 mg/100ml |
| Iced tea (bottled) | 355 ml | 45 mg | 12.7 mg/100ml |
| Herbal tea (caffeine-free) | 240 ml | 0 mg | 0 mg/100ml |
How tea compares to coffee and energy drinks
Teas generally deliver less caffeine per 240 ml than brewed coffee and many energy drinks. For reference, drip coffee (240 ml) in the dataset is 96 mg, cold brew (240 ml) = 200 mg, and a typical energy drink (250–473 ml) ranges from 80 mg to 300 mg. Yerba mate and strong matcha come closest to a light brewed coffee.
Why caffeine numbers vary: brewing, leaf and format
Leaf type and processing
Black, oolong, green and white all come from Camellia sinensis; processing changes polyphenols and soluble caffeine extraction. Generally: black (oxidized) ≈ the dataset value 47 mg/240 ml, oolong lower (37 mg), green lower still (28 mg) and white lowest (16 mg).
Preparation variables
Steep time, water temperature, leaf quantity and leaf particle size matter. Longer steeps and hotter water extract more caffeine; matcha is powdered whole leaf so a 1 tsp matcha infusion gives the whole-leaf caffeine (70 mg per 240 ml in the dataset) rather than a fraction.
Tea blends and concentrates
Chai lattes use black tea plus milk and spices (50 mg/240 ml here). Bottled iced teas are often brewed then diluted—dataset shows 45 mg per 355 ml.
Caffeine decay: how much remains hours after drinking
Use the population-average half-life of 5.7 hours to estimate remaining caffeine. An approximate rule: after ~3 h ≈ 69% remains, 6 h ≈ 48%, 9 h ≈ 33%, 12 h ≈ 23%.
| Original dose (mg) | After 3 h (~69%) | After 6 h (~48%) | After 9 h (~33%) | After 12 h (~23%) |
|---|---|---|---|---|
| Black tea — 47 mg | ~32 mg | ~23 mg | ~16 mg | ~11 mg |
| Matcha — 70 mg | ~48 mg | ~34 mg | ~23 mg | ~16 mg |
| Yerba mate — 85 mg | ~59 mg | ~41 mg | ~28 mg | ~20 mg |
| Green tea — 28 mg | ~19 mg | ~13 mg | ~9 mg | ~6 mg |
Example: if you drink a matcha (70 mg) at 3 pm, expect ~34 mg remaining by 9 pm — enough to affect sleep in sensitive people.
Health and safety context
Recommended limits
For healthy adults, the FDA and many authorities cite about 400 mg/day as a safe upper bound. For pregnancy, expert guidance (including EFSA and Mayo Clinic summaries) suggests limiting to about 200 mg/day. The American Academy of Pediatrics discourages routine caffeine for adolescents.
Symptoms and caution
Watch for heart palpitations, anxiety, insomnia, or gastrointestinal upset. Very high daily totals (several hundred milligrams beyond recommended limits) raise overdose risk; seek medical care for severe symptoms. For personalized advice, consult your clinician.
Practical tips for lowering or tracking intake
- Choose white or green tea to cut caffeine: white tea = 16 mg/240 ml, green = 28 mg/240 ml.
- Use shorter steeps and cooler water to reduce extraction.
- For a no-caffeine alternative, pick herbal tisanes (0 mg in dataset).
- Track servings and totals with an app like CoffeeLog to automatically sum mg/day and compare to the 400 mg guideline.
Regional and cultivar differences (what "Assam" or "Darjeeling" means for caffeine)
Region, cultivar and harvest (first flush vs later flush) change leaf chemistry. Black Assam or English Breakfast blends often lean toward the higher end of black tea values (the dataset lists English Breakfast at 50 mg/240 ml). Darjeeling and single-origin green teas typically yield lower caffeine than robust black blends.
Bottom line
"Tea caffeine content" spans roughly 0–85 mg in common servings: white tea about 16 mg, green 28 mg, black around 47–50 mg, matcha 70 mg and yerba mate 85 mg. Use the decay numbers above and guideline limits (≈400 mg/day for adults, ≈200 mg/day pregnancy) to plan timing and total daily intake.
Track daily totals and timing with CoffeeLog to see how a cup at 3 pm affects evening caffeine remaining.
Frequently asked questions
How much caffeine is in a cup of black tea?
A standard 240 ml cup of black tea contains 47 mg of caffeine according to the dataset; English Breakfast is listed at 50 mg per 240 ml.
Does matcha have more caffeine than green tea?
Yes—matcha (1 tsp in 240 ml) is 70 mg in the dataset, while brewed green tea is 28 mg per 240 ml, because matcha uses powdered whole leaf.
How long does tea caffeine last in your body?
Using a population half-life of 5.7 hours: ~69% remains after 3 h, ~48% after 6 h, ~33% after 9 h and ~23% after 12 h. For a 70 mg matcha, ~34 mg remains at 9 hours.
Is herbal tea caffeine-free?
Yes; herbal tisanes in the dataset are 0 mg per 240 ml and are a reliable caffeine-free option.
Can pregnant people drink tea and how much caffeine is safe?
Pregnancy guidance referenced by EFSA and medical sources suggests limiting caffeine to about 200 mg/day; count tea toward that total and consult your healthcare provider.
How can I reduce caffeine from tea without switching types?
Steep for less time, use cooler water and fewer leaves; choose white tea (16 mg/240 ml) or shorter steeps to lower extraction while keeping the same tea.