An 8-ounce cup of English Breakfast tea contains roughly 48 mg of caffeine, while the same size cup of brewed coffee delivers about 96 mg. That makes coffee approximately twice as strong as English Breakfast tea, cup for cup. But both drinks have a surprising amount of variability depending on how you prepare them.
The Basic Numbers
For a standard 8-ounce serving, here’s what you’re looking at:
- Brewed coffee: 96 mg of caffeine (can range from 90 to 200 mg)
- English Breakfast tea: 48 to 50 mg of caffeine
That range for coffee is wide because it depends on the bean variety, grind size, and brewing method. The tea side is more predictable, but steeping habits can push the number meaningfully higher or lower.
How Steeping Time Changes Your Tea
The caffeine in your cup of English Breakfast tea is not a fixed number. It depends heavily on how long you leave the tea bag or leaves in the water. At one minute of steeping, only about 18% of the available caffeine has been extracted. By three minutes, that jumps to 48%. And at five minutes, you’re pulling out roughly 69% of the caffeine in the leaves.
In practical terms, a quick one-minute dunk might give you closer to 15 mg of caffeine, while a strong five-minute brew could push past 55 mg. If you’re drinking English Breakfast tea specifically to get a caffeine boost in the morning, letting it steep for the full three to five minutes makes a real difference. If you’re trying to keep caffeine low, a shorter steep helps more than you might expect.
Water Temperature Matters Too
Hotter water extracts caffeine faster. Research published through the American Chemical Society found that tea steeped at boiling temperature (100°C) released caffeine at a significantly higher rate than tea steeped at lower temperatures like 50°C or room temperature. English Breakfast tea is a black tea, so it’s traditionally brewed with fully boiling water, which means you’re getting close to maximum caffeine extraction compared to, say, a green tea brewed at a lower temperature. This is one reason black teas consistently land at the top of the caffeine range among teas.
Why Coffee Varies So Much
The 96 mg average for brewed coffee is just a midpoint. A strong pour-over with finely ground beans can easily clear 150 mg per cup, and some specialty brews push past 200 mg. The bean variety is the biggest factor. Robusta beans, commonly used in instant coffee and espresso blends, contain nearly double the caffeine of Arabica beans, which are the standard for most drip coffee. Your grind size, water-to-coffee ratio, and brew time all layer on top of that.
If you’re comparing your English Breakfast tea to espresso-based drinks like lattes or cappuccinos, the math shifts a bit. Those drinks use concentrated shots rather than a full 8-ounce brew, so the total caffeine per drink depends on how many shots are in it. A single-shot latte might land closer to 63 mg, which isn’t dramatically more than a well-steeped cup of English Breakfast.
How Many Cups Can You Have?
The FDA considers 400 mg of caffeine per day a safe amount for most healthy adults. That ceiling gives you room for about four cups of brewed coffee or roughly eight cups of English Breakfast tea before you’d approach the limit. In practice, most people who drink tea throughout the day stay well under that threshold without thinking about it. Coffee drinkers hit it faster, especially if they’re ordering large sizes from cafés, which often contain 12 to 16 ounces rather than the standard 8-ounce measurement those caffeine numbers are based on.
The Decaf Option
If you’re cutting back on caffeine but still want the ritual, decaf versions of both drinks aren’t completely caffeine-free. Decaf coffee retains about 7 mg per cup, roughly 93% less than regular. Decaf tea keeps even less, around 2 mg per cup, which is 96% less than a standard brew. So decaf English Breakfast tea is about as close to zero as you can get while still drinking real tea.
Switching From Coffee to Tea
Many people searching this comparison are considering a swap. If you’re used to coffee’s 96 mg hit and switch to English Breakfast tea, you’ll be cutting your caffeine roughly in half per cup. That’s enough of a drop that you may notice it for a few days, particularly if you were drinking multiple cups of coffee. Some people find that brewing their tea strong (five minutes, boiling water) and having two cups in the morning bridges the gap comfortably. Two strong cups of English Breakfast tea lands you around 100 to 110 mg, which is close to what a single cup of coffee delivers.
The experience of the caffeine also feels different to many people, though the caffeine molecule is identical in both drinks. Tea contains an amino acid called L-theanine that promotes calm focus, which is why tea drinkers often describe the effect as “alert but not jittery.” Coffee hits faster and harder, partly because the higher dose arrives in a more concentrated form.