Pick your tea, the water and how long you steep it. You see the caffeine a 2025 laboratory analysis measured in that tea brewed that way — 2 g in 200 mL, the way it brewed 68 teas — beside the same cup of coffee and the FDA’s 400 mg a day. Where the study did not measure your exact minutes, you get the range between the two it did.
Your cup holds
23 mg of caffeine Black tea, 5 min at 100 °C (212 °F, boiling) — 2 g in 200 mL (6.8 fl oz), bags and loose leaf together
The same 200 mL of brewed coffee: 80.1 mg (USDA) — 3.5× the caffeine of this tea.
The average of 41 black teas (coefficient of variation 35.6%) — one brand can sit well above or below it.
A cup like this is 6% of the 400 mg a day the FDA cites for most adults.
| Tea | 2 min | 5 min | 10 min |
|---|---|---|---|
| Green tea 12 teas | 15 | 25 | 27 |
| White tea 5 teas | 16 | 22 | 31 |
| Yellow tea 2 teas | 26 | 42 | 53 |
| Oolong tea 4 teas | 14 | 25 | 29 |
| Black tea 41 teas | 17 | 23 | 27 |
| Pu-erh tea 2 teas | 19 | 28 | 40 |
| Brewed coffee USDA, same 200 mL | 80.1 | ||
This is not medical advice. It shows what one laboratory measured in commercial teas; your tea, its weight in the cup and your water make your own number. If you are pregnant, take a heart or blood-pressure medicine, or are sensitive to caffeine, ask your doctor how much is right for you.
Brewed with boiling water, 2 g of black tea in 200 mL held 17 mg of caffeine after 2 minutes, 23 mg after 5 and 27 mg after 10 — the average of 41 black teas in a 2025 laboratory analysis. Green tea: 15, 25 and 27 mg. The same 200 mL of brewed coffee holds 80 mg (USDA): about three and a half times a 5-minute black tea.
How to use it
Pick your tea, type how many minutes you steep it, choose boiling water or 80 °C (176 °F) and, for black, green or white tea, whether it is a bag or loose leaf. You see the caffeine measured in that tea brewed that way, a bar against the same 200 mL of coffee, how much the teas varied, and the share of the FDA’s 400 mg a day. The study measured 2, 5 and 10 minutes: at 3 minutes you get the range between its 2- and 5-minute figures, never an invented number in between.
Where the numbers come from
Ayakdaş and Ağagündüz (Foods, 2025) bought 68 commercial teas in Istanbul — 41 black, 12 green, 5 white, 4 oolong, 4 pu-erh and 2 yellow — and measured caffeine by HPLC (their Table 2 reports the pu-erh figures on 2 teas, and so does this page). Their method: “For loose-leaf samples, 2 g each of dry tea were brewed with 200 mL of water in a sealed glass herbal tea brewing container.” Bags were dipped 5–6 times, then brewed the same way, at 80 °C and 100 °C, for 2, 5 and 10 minutes. Every figure here is their Table 2 (by type) or Table 3 (bag or loose), for 2 g in 200 mL — a different amount of tea or water is a different brew, so this page never stretches their numbers to another cup.
They also say why their black tea reads lower than many published figures: “However, most of the black tea samples analyzed in this study were from Turkey and had shorter brewing times (2–10 min), which may have caused the lower values”. USDA’s figure for brewed black tea, from its own lab samples, is 20 mg per 100 g — 40 mg in the same 200 mL. Both are measurements; the spread between them is what “it depends on the tea” means.
| Tea | Teas measured | 80 °C | Boiling |
|---|---|---|---|
| Black tea | 41 | 23 | 23 |
| Green tea | 12 | 23 | 25 |
| White tea | 5 | 26 | 22 |
| Oolong tea | 4 | 11 | 25 |
| Pu-erh tea | 2 | 25 | 28 |
| Yellow tea | 2 | 37 | 42 |
Two things move the number most. Time: “Similarly, in the literature, caffeine concentration increased with brewing time in high-temperature constant water brews; however, this increase slowed down past 3–5 min”. And the bag: “In black tea, cup-sized bags yielded higher caffeine levels (39 ± 9.9 mg/200 mL) than loose-leaf (24 ± 7.2 mg/200 mL) and teapot bags (p < 0.001)." Their summary: "In conclusion, fermentation rate, brewing conditions, and serving method were found to influence the caffeine and L-theanine levels of tea infusions."
Earl Grey and chai
No analysis we found measured either one separately. Both are sold as black tea: Earl Grey bags list “BLACK TEA, OIL OF BERGAMOT.” and chai bags list black tea first, then ginger, cinnamon, pepper, cloves and cardamom (labels in USDA’s Branded Foods database). So this page reads them as black tea and says so. A coffee-shop chai latte is a different drink — made from a concentrate, with milk — and is not on this page.
Worked examples
- Black tea, 5 minutes, boiling (the page’s example): 23 mg — the same 200 mL of coffee has 80 mg, 3.5× as much.
- A cup-sized black tea bag, 3 minutes, boiling: between 23 mg (2 minutes) and 33 mg (5 minutes).
- Green tea, 2 minutes at 80 °C: 11 mg — 7.3× less than the coffee.
- Earl Grey, 12 minutes: the study stopped at 10 minutes, so you see its 10-minute black tea figure, 27 mg, and the page says it did not measure longer.
Common mistakes
- Taking one figure as every tea’s. The black teas varied by a third or more around their average (a coefficient of variation of 34–45%); the green teas by more.
- Comparing a big mug of coffee with a small cup of tea. This page puts coffee in the same 200 mL.
- Thinking a long steep keeps adding caffeine at the same rate. The rise slows after the first few minutes.
- Assuming green tea is always the low one. At 5 minutes in boiling water, green tea (25 mg) measured about the same as black (23 mg).
Frequently asked questions
How much caffeine is in black tea?
In the 2025 analysis, 2 g in 200 mL of boiling water held 17 mg at 2 minutes, 23 mg at 5 and 27 mg at 10 (41 teas). USDA’s brewed black tea is 40 mg in the same 200 mL. The tea, the bag and the minutes make the difference.
How much caffeine is in green tea?
11 to 28 mg in 2 g / 200 mL, depending on the water and the minutes — 25 mg after 5 minutes in boiling water (12 teas).
How much caffeine is in Earl Grey tea?
Earl Grey is black tea with bergamot oil, and no analysis we found measured it separately — read it as black tea: about 23 mg in 2 g / 200 mL after 5 minutes in boiling water.
How much caffeine is in chai tea?
A chai tea bag is black tea plus spices; read it as black tea. A coffee-shop chai latte is made from a concentrate and is a different question.
Does tea have more caffeine than coffee?
Not cup for cup. In the same 200 mL, brewed coffee has 80 mg (USDA); the teas in this analysis ranged from 4 to 53 mg depending on the type, the water and the minutes.
Does steeping tea longer add caffeine?
Yes, in most of the teas — black tea went from 17 to 27 mg between 2 and 10 minutes in boiling water — but the study notes the rise slows after the first 3 to 5 minutes.
For coffee, energy drinks and the rest, see the Caffeine Content Chart; for when the caffeine leaves your system, the Caffeine Half-Life Calculator; for the L-theanine in tea, Matcha vs Coffee.
Read next
- Best tea for brain fog — what does the science say?
- Caffeine as a nootropic
- L-Theanine nootropic review
- Is there caffeine in nootropics?
This is not medical advice. It shows what one laboratory measured in commercial teas and what USDA lists for coffee; your own tea, the amount you use and your water make your own number. If you are pregnant, take a heart or blood-pressure medicine, or are sensitive to caffeine, ask your doctor or pharmacist how much is right for you. Some links on this site are affiliate links: I buy what I review at full price, and a commission never changes a verdict.