How much caffeine is in English Breakfast tea?

A standard 240 ml (8.1 fl oz) cup of English Breakfast tea contains 50 mg of caffeine, which works out to 20.8 mg per 100 ml. That is just over half the caffeine of a same-sized drip coffee (96 mg), placing it in the moderate range for a brewed beverage. The caffeine from a cup of English Breakfast tea is absorbed over 15 to 45 minutes, with peak blood levels typically reached around 30 to 60 minutes after drinking, producing a gentle lift in alertness that many people find less jittery than coffee.

At 50 mg, one cup accounts for 13% of the widely cited 400 mg daily maximum for healthy adults set by the U.S. Food and Drug Administration and the European Food Safety Authority. For most people, this dose is well below the threshold that triggers pronounced side effects, though individual sensitivity varies. English Breakfast is a black tea blend, and its caffeine content sits near the middle of the black tea spectrum, slightly higher than the average plain black tea but lower than many coffee and energy drink options.

Because English Breakfast is a blend of Assam, Ceylon, and sometimes Kenyan teas, the caffeine content can shift depending on the proportions used by each brand. The 50 mg figure is a representative value drawn from laboratory analyses of commercially available tea bags and loose-leaf samples, as compiled in the USDA FoodData Central database and other public sources.

How long English Breakfast tea stays in your system

Caffeine elimination follows first-order kinetics with a population-average half-life of 5.7 hours. Starting with a 50 mg dose, the amount remaining in the body can be calculated as 50 × 0.5^(hours / 5.7). After 3 hours, approximately 35 mg remain (50 × 0.5^(3/5.7) = 50 × 0.5^0.526 = 50 × 0.693 ≈ 34.7 mg). After 6 hours, the figure drops to 24 mg; after 9 hours, 17 mg; and after 12 hours, about 12 mg. This decay pattern means that even a single morning cup of English Breakfast tea leaves a measurable caffeine residue well into the afternoon and evening.

For someone who drinks a 50 mg cup at 15:00, the body still holds around 24 mg at 21:00, 17 mg at midnight, and 12 mg at 03:00 the next morning. While 24 mg is a small amount compared with a full cup of coffee, it can be enough to delay sleep onset or reduce deep sleep in caffeine-sensitive individuals. The half-life of 5.7 hours is an average; genetic differences and factors like pregnancy, liver function, and smoking can extend or shorten it considerably. The interactive caffeine half-life calculator lets you model your own elimination timeline with a custom half-life.

With 50 mg per cup, an adult can consume up to 8 cups of English Breakfast tea in a day and remain at or below the FDA and EFSA daily guidance of 400 mg. That ceiling assumes no other caffeine sources and a healthy adult without underlying conditions. For pregnant individuals, the EFSA recommends limiting daily caffeine to 200 mg, which translates to 4 cups of English Breakfast tea. Adolescents are often advised to cap caffeine at 2.5 mg per kilogram of body weight per day; for a 50 kg (110 lb) teenager, that means no more than 125 mg, or 2.5 cups. These are upper bounds, not targets, and many people feel better with less.

The timing of your last cup matters for sleep. Using the average half-life of 5.7 hours, a 50 mg dose consumed 6 hours before a 23:00 bedtime leaves about 24 mg in circulation at lights-out. While 24 mg is a fraction of a full cup, research by Drake et al. (2013) published in the Journal of Clinical Sleep Medicine found that even 400 mg taken 6 hours before bed reduced sleep by over an hour; smaller doses can still fragment sleep architecture in sensitive individuals. To minimize sleep disruption, a common rule of thumb is to stop caffeine intake 8–10 hours before bed, which for a 23:00 bedtime means finishing your last cup by 13:00–15:00. Our latest cup before bedtime calculator can give you a personalized cutoff based on your target sleep time and individual half-life.

People with slow caffeine metabolism—a genetic variant carried by about half the population—may have a half-life of 8–9 hours instead of 5.7. For them, the 50 mg from an afternoon tea lingers much longer, and even a lunchtime cup could interfere with sleep. If you notice that tea in the afternoon keeps you awake, consider switching to a lower-caffeine option like white tea (16 mg) or a caffeine-free herbal infusion after midday. The safe daily limit by body weight tool provides further individualization.

Within the tea category, English Breakfast at 50 mg per 240 ml is on the stronger side for a pure Camellia sinensis infusion. It exceeds plain black tea (47 mg), Earl Grey (47 mg), oolong (37 mg), green tea (28 mg), and white tea (16 mg). The only common tea preparations that deliver more caffeine are matcha, at 70 mg per 240 ml when made with one teaspoon of powder, and yerba mate, an herbal infusion that provides 85 mg per 240 ml. Chai latte, which combines black tea with milk and spices, also clocks in at 50 mg for a 240 ml serving, making it a direct match. Bottled iced tea, despite a larger 355 ml serving, contains only 45 mg, illustrating how processing and dilution can lower caffeine density.

When placed beside coffee, English Breakfast tea is clearly the milder option. A 240 ml drip coffee contains 96 mg, nearly double the 50 mg in tea. A single 30 ml espresso shot packs 63 mg, meaning that a small espresso already exceeds a full cup of English Breakfast. Energy drinks amplify the difference: a 250 ml can of Red Bull has 80 mg, and a 473 ml Monster Energy contains 160 mg, or more than three cups of tea. This positioning makes English Breakfast a useful stepping stone for those looking to reduce caffeine intake without eliminating it entirely. Two cups of English Breakfast (100 mg total) roughly equal one cup of drip coffee, so a simple swap can halve your caffeine load while preserving the ritual of a hot beverage.

The experience of drinking English Breakfast tea differs from coffee not just in caffeine quantity but in the presence of L-theanine, an amino acid that promotes calm focus. While this does not change the milligram count, it helps explain why 50 mg of tea caffeine often feels smoother than the same amount from a caffeine pill or energy drink. For a side-by-side numerical comparison of any two drinks, use our caffeine comparison tool.

What changes the number for English Breakfast tea

The 50 mg figure is a useful benchmark, but the actual caffeine in a cup of English Breakfast tea can vary by 20 mg or more depending on how the tea is prepared and which brand you choose. English Breakfast is not a standardized product; it is a blend of black teas, typically Assam, Ceylon, and Kenyan, and the caffeine content of the raw leaves differs by origin, harvest, and processing. A tea bag that contains a higher proportion of Assam leaves, for example, may yield a slightly higher caffeine extraction than one dominated by Ceylon.

Brewing method is the largest controllable factor. The main variables are:

• Steep time: Caffeine extraction increases with time, but it plateaus. A 1-minute steep extracts roughly half the caffeine of a 5-minute steep. Most recommendations call for 3–5 minutes, which aligns with the 50 mg estimate.
• Water temperature: Boiling water (100 °C) extracts caffeine more efficiently than water at 80 °C. Using water just off the boil is standard for black tea.
• Tea-to-water ratio: One tea bag per 240 ml is typical, but loose-leaf drinkers may use 2–3 grams, which can push caffeine higher. A larger mug of 350 ml with the same bag yields a weaker brew per ml but more total caffeine if the bag is steeped fully.
• Leaf grade: Broken leaf grades (common in tea bags) release caffeine faster than whole leaves. Dust and fannings, often found in mass-market bags, can produce a stronger cup in the same steep time.

Published values for English Breakfast tea range from about 40 mg to 70 mg per 240 ml cup. The USDA FoodData Central lists an average of 47 mg for generic black tea, while other laboratory surveys report means of 50–55 mg for English Breakfast blends. Decaffeinated English Breakfast tea typically retains 2–5 mg of caffeine per cup, which is negligible for most people but still present. If you are counting milligrams precisely, the only way to know your exact dose is to measure the same brand and brewing routine consistently; otherwise, treat the 50 mg as a reasonable midpoint.

For comparisons with other tea types, see our pages on black tea (47 mg), Earl Grey (47 mg), and green tea (28 mg). The caffeine content of English Breakfast sits comfortably within the black tea family, and the variation from cup to cup is similar to what you would encounter with any brewed beverage.

Where this figure comes from

The 50 mg figure on this page is a composite estimate drawn from multiple public databases and laboratory analyses. The USDA FoodData Central lists an average caffeine content of 47 mg per 240 ml for generic brewed black tea. English Breakfast blends, which often use a higher proportion of Assam and Kenyan leaves, typically test slightly higher, with published means clustering around 50–55 mg. The Mayo Clinic caffeine chart reports 47 mg per 8-ounce cup of black tea, while the EFSA 2015 safety opinion notes a range of 40–50 mg per 150 ml serving for black tea, which scales to roughly 64–80 mg per 240 ml at the high end, though those values likely reflect stronger European brewing habits. We selected 50 mg as a conservative, representative midpoint that aligns with the most commonly cited U.S. figures.

Disagreement among sources is normal for brewed beverages because caffeine extraction depends on steep time, water temperature, leaf grade, and blend composition—variables that no single study can fully standardize. We monitor new research and updates to authoritative databases, and we will revise this figure if a large, well-controlled survey of commercial English Breakfast tea products provides a more accurate mean. Our entire dataset is open and version-controlled; you can inspect the raw numbers and the provenance of each entry on the open caffeine dataset page. If you have access to laboratory results that differ materially, we welcome corrections.

Bottom line

A 240 ml cup of English Breakfast tea delivers 50 mg of caffeine, which is about half the caffeine of a same-sized drip coffee (96 mg) and 13% of the 400 mg daily maximum for healthy adults. After 6 hours, roughly 24 mg remain in the body, and after 12 hours, about 12 mg. This moderate dose makes English Breakfast a sensible choice for those who want a gentle lift without the intensity of coffee or energy drinks, and up to 8 cups can fit within the standard daily limit. Individual sensitivity, pregnancy status, and bedtime timing should guide personal consumption, but as a benchmark, 50 mg per cup is a well-established, evidence-backed figure.