A standard 8-ounce cup of tea contains roughly 15 to 70 mg of caffeine, depending on the type. Black tea sits at the high end, white tea at the low end, and green and oolong fall in between. For context, the same size cup of brewed coffee delivers about 96 mg, so even the strongest black tea has meaningfully less caffeine than a typical coffee.
Caffeine by Tea Type
The differences between tea types come down to how the leaves are processed after harvest. Black tea leaves are fully oxidized, which changes their chemical structure and tends to produce higher caffeine levels in the brewed cup. White tea leaves are minimally processed and typically yield the least caffeine. Here’s what to expect from an 8-ounce cup brewed at home:
- Black tea: 40 to 70 mg
- Oolong tea: 30 to 55 mg
- Green tea: 20 to 45 mg
- White tea: 15 to 40 mg
These ranges are wide because caffeine content varies from one product to another. Two different black teas can land at opposite ends of the 40 to 70 mg range based on the specific plant variety, where it was grown, and when the leaves were harvested. Younger leaves and leaf buds tend to contain more caffeine than older, larger leaves, which is why some white teas (made from young buds) occasionally surprise people by testing higher than expected.
How Brewing Changes the Numbers
The caffeine listed on a tea package reflects a general estimate, but how you actually make your cup matters just as much as what’s in the bag. Two variables dominate: water temperature and steeping time. Hotter water pulls caffeine out of the leaves faster, and longer steeps give it more time to dissolve. A black tea steeped for five minutes in boiling water will have noticeably more caffeine than the same tea steeped for two minutes in slightly cooler water.
This is partly why green tea tends to be lower in caffeine than black tea in practice. Green tea is usually brewed at lower temperatures (around 170 to 180°F) and for shorter periods, while black tea calls for boiling or near-boiling water and longer steeps. If you brewed green tea leaves in boiling water for five minutes, the caffeine gap between green and black would shrink considerably. So your brewing habits give you a real lever to pull. If you want less caffeine from any tea, use cooler water and steep for a shorter time.
Matcha Is a Different Story
Matcha breaks the pattern for green tea because you’re consuming the entire leaf, ground into a fine powder, rather than steeping leaves and discarding them. A typical matcha serving uses 2 to 4 grams of powder (roughly half to one teaspoon), which delivers 38 to 176 mg of caffeine. That upper range overlaps with coffee, making matcha one of the few teas that can match or exceed a cup of drip brew.
The wide range reflects how much powder you use. A light, thin matcha with half a teaspoon lands around 38 mg. A thick, traditional preparation with a full teaspoon can push past 100 mg. If you’re switching from coffee to matcha expecting a gentler caffeine hit, pay attention to how much powder goes into your cup.
Tea vs. Coffee: A Direct Comparison
According to Mayo Clinic data, an 8-ounce cup of brewed coffee contains about 96 mg of caffeine. Brewed black tea comes in at roughly 48 mg, and brewed green tea at about 29 mg. That means a cup of coffee delivers roughly double the caffeine of black tea and more than triple that of green tea.
Bottled and ready-to-drink teas tend to be lower still, with black bottled tea averaging around 26 mg per 8 ounces. The brewing process used in commercial production and the dilution with water and ice both reduce the final concentration. If you’re grabbing a bottled tea from a convenience store, you’re likely getting less caffeine than you would from a cup you brewed at home.
For people tracking their intake, the FDA considers up to 400 mg of caffeine per day a safe amount for most healthy adults. That’s the equivalent of roughly 6 to 10 cups of black tea, or about 4 cups of coffee. Most tea drinkers stay well under this threshold without trying.
How Much Caffeine Is in Decaf Tea
Decaffeinated tea isn’t caffeine-free. To carry a “decaf” label, tea needs to have about 96% of its original caffeine removed. In practice, that leaves around 2 mg per cup, a trace amount that has no noticeable stimulant effect for the vast majority of people. If you’re avoiding caffeine entirely for medical reasons, herbal teas (chamomile, rooibos, peppermint) are naturally caffeine-free since they aren’t made from the tea plant at all.