How Black Tea's Caffeine Content Compares To Coffee

We've all heard the expression "Don't talk to me before my coffee" or some variation of it. With the hustle and bustle of daily life, caffeine is viewed by many as a necessity, and for the majority of Americans, coffee is the preferred caffeine delivery system. According to Statista, in 2024, 73% of surveyed American consumers reported drinking coffee every day, and a 2023 survey performed by SleepFoundation.org found that of the 94% of respondents who regularly drink caffeinated beverages, 51% most often drink coffee.

That doesn't mean coffee is the only drink in town with a hefty dose of caffeine, however. Energy drinks, sodas, and certain types of tea pack a caffeinated punch as well, and may be preferable for those who want an energy boost but don't like the taste or sensation of drinking coffee. Of the standard bagged or loose-leaf teas, black tea varieties contain the most caffeine. In fact, an average cup of black tea generally contains anywhere from 47 to 55 milligrams. A cup of coffee, on the other hand, typically contains between 96 and 128 milligrams of the stimulant, while a shot of espresso has more caffeine – as much as 63 milligrams of the stuff in a single ounce.

Put another way, a typical cup of tea has about half as much caffeine as a cup of coffee. In this context, it's perhaps understandable that coffee became the steamy energy booster of choice for most busy Americans. Those seeking out a gentler boost from a drink with hydrating health benefits would be well-served by a hot mug of black tea, however.

At this point, you might be wondering how the different types of loose-leaf tea — black, green, oolong, white, and herbal — differ, and why black teas have the most caffeine. First, you should know that all "true" teas come from the plant Camellia sinensis, which contains caffeine. This means that herbal teas — the product of other plants — don't technically count, and why they are the only caffeine-free teas.

Since the other "true" types of tea start from the leaves of the same plant, they are differentiated by their methods of harvesting and production. Black teas, in particular, are unique in that their leaves are fully oxidized, which gives them a more robust flavor. It's thought that this is also why black teas have a higher caffeine percentage on average, but in truth, it's more complicated and varied than that. Compared to black tea, green teas may have between 20 and 45 milligrams of caffeine, and white teas anywhere from 6 to 60 milligrams.

Surprisingly, the differing caffeine content of teas and coffees is not a direct result of their base ingredients. In unprocessed form, tea leaves contain 3.5% caffeine, while coffee beans contain between 1 and 2.2% — so by that metric, you would actually expect tea to be more caffeinated than coffee. However, the coffee brewing process uses hotter water than tea, and more beans than tea uses leaves, both of which contribute to its higher caffeine content. That also means that to brew extra-strong tea, you should use hotter water and more tea leaves.