Coffee has roughly twice as much caffeine as tea. An 8-ounce cup of brewed coffee contains about 96 mg of caffeine, while the same size cup of black tea has about 48 mg. That gap holds across most comparisons, though the exact numbers shift depending on the type of tea, the coffee bean variety, and how you brew either drink.
Cup-for-Cup Caffeine Comparison
For a standard 8-ounce serving, here’s what you’re looking at across the most common tea types:
- Brewed coffee: 90 to 200 mg (average around 96 mg)
- Black tea: 40 to 70 mg
- Matcha: 60 to 70 mg per standard 2-gram serving
- Oolong tea: 30 to 55 mg
- Green tea: 20 to 45 mg
- White tea: 15 to 40 mg
- Decaf tea: 2 to 5 mg
- Herbal tea (chamomile, peppermint, rooibos): 0 mg
Even the strongest black tea rarely matches the low end of coffee’s range. The only tea that comes close is matcha, because you’re whisking powdered whole leaves into water and consuming everything, not just steeping and discarding the leaf. That said, most people drink matcha in smaller portions than a full 8-ounce mug.
A few herbal drinks blur the line. Yerba mate delivers 30 to 85 mg per 8-ounce cup depending on preparation, and guayusa lands around 40 to 70 mg. Both are technically tisanes, not true tea from the Camellia sinensis plant, but they’re sold alongside teas and can rival coffee in caffeine.
Why Serving Size Changes the Math
The 8-ounce comparison is tidy, but most people don’t drink 8 ounces of coffee. The most popular takeaway cup in coffee shops is 12 ounces, and large orders run 16 to 20 ounces. A 12-ounce brewed coffee hits roughly 144 mg of caffeine, and a 16-ounce cup pushes close to 192 mg. Tea drinkers, meanwhile, often refill from the same teabag or leaves, which yields progressively less caffeine with each steep. So the real-world gap between coffee and tea is often wider than the per-ounce numbers suggest.
What Affects Caffeine in Your Coffee
Not all coffee beans carry the same dose. Arabica beans, which make up the majority of specialty and grocery-store coffee, contain about 1.2 to 1.5% caffeine by weight. Robusta beans pack nearly double that, around 2.2 to 2.7%. If your coffee tastes noticeably more bitter and punchy than usual, there’s a good chance it includes robusta beans, and your caffeine intake is higher than the standard averages.
Brew method matters too. Drip and pour-over coffee tend to extract more caffeine because hot water passes through grounds for several minutes. Espresso is concentrated but served in tiny 1- to 2-ounce shots, so a single shot actually contains less total caffeine (around 63 mg) than a full mug of drip coffee. Order a double espresso latte, though, and you’re back up around 126 mg before accounting for the milk.
What Affects Caffeine in Your Tea
Water temperature and steeping time are the two biggest variables. Research on green tea brewing found that caffeine extraction jumps significantly in the first three minutes, reaching about 10 mg per 100 ml at 75°C (167°F) and about 11 mg per 100 ml at 85°C (185°F). After three minutes, additional steeping time doesn’t meaningfully increase caffeine. So a quick 1-minute steep gives you a milder cup, while a 3-minute or longer brew pulls most of the available caffeine out of the leaf.
Leaf grade also plays a role. Teas made from younger leaves and buds, like many white and high-quality green teas, can contain more caffeine per gram than coarser, older leaves. But because they’re typically brewed at lower temperatures with shorter steep times, the caffeine in your cup ends up lower. The type of tea plant, growing conditions, and even harvest season all contribute, which is why caffeine ranges for each category are so wide.
Tea Feels Different for a Reason
Many tea drinkers report a smoother, more sustained energy boost compared to coffee’s sharper spike. That’s not just perception. Tea contains an amino acid called L-theanine that promotes alpha brain wave activity, a pattern associated with calm, focused alertness. When L-theanine and caffeine are consumed together, as they naturally are in tea, the combination appears to improve attention and mental performance while softening the jittery edge caffeine can produce on its own.
This is why some people find tea better suited for long stretches of concentration. You’re getting a lower caffeine dose paired with a compound that takes the edge off, rather than a higher dose without that buffer. Coffee has trace amounts of L-theanine but not nearly enough to produce the same balancing effect.
How This Fits Into Daily Limits
The FDA considers up to 400 mg of caffeine per day safe for most healthy adults. That translates to about four 8-ounce cups of brewed coffee or roughly eight cups of black tea. In practice, most coffee drinkers hit two to three mugs a day and land comfortably within that range. Tea drinkers would need to consume significantly more volume to approach the same ceiling.
If you’re trying to cut back on caffeine without giving it up entirely, switching from coffee to black tea roughly halves your intake cup for cup. Moving to green tea cuts it further. And if you want the ritual of a hot drink with zero caffeine, herbal teas like chamomile, peppermint, and rooibos contain none at all.