How much caffeine is in Earl Grey tea?

A 240 ml (8.1 fl oz) cup of Earl Grey tea contains 47 mg of caffeine, which works out to 19.6 mg per 100 ml. This places it at exactly half the caffeine of a same-sized drip coffee (96 mg) and squarely in the moderate range for tea-based beverages. Earl Grey is a black tea scented with bergamot oil, and the caffeine comes entirely from the tea leaves—the bergamot adds no stimulant effect. The absorption of caffeine begins in the stomach and small intestine, with peak plasma concentration typically reached 30 to 60 minutes after drinking. For most adults, 47 mg produces a gentle lift in alertness and focus, often described as a clean, sustained energy without the sharp spike or jitteriness that can accompany a stronger coffee. This single serving accounts for 12% of the 400 mg daily limit that the U.S. Food and Drug Administration considers safe for healthy adults.

How long Earl Grey tea stays in your system

Caffeine follows first-order elimination kinetics with a population-average half-life of 5.7 hours. Starting from the 47 mg dose in a standard Earl Grey, the amount remaining in the bloodstream is calculated as 47 × 0.5^(hours / 5.7). After 3 hours, approximately 33 mg remain (47 × 0.5^(3/5.7) = 47 × 0.694 = 32.6 mg). After 6 hours, 23 mg remain (47 × 0.5^(6/5.7) = 47 × 0.482 = 22.7 mg). After 9 hours, 16 mg remain (47 × 0.5^(9/5.7) = 47 × 0.335 = 15.7 mg). After 12 hours, 11 mg remain (47 × 0.5^(12/5.7) = 47 × 0.232 = 10.9 mg). These values are not exact for every individual—liver enzyme activity, age, pregnancy status, and genetic factors can speed or slow clearance, with some people metabolizing caffeine twice as fast and others half as fast—but they represent a reliable central estimate.

If a person drinks a 47 mg Earl Grey at 15:00, by 21:00 they still have about 23 mg active, and by midnight roughly 16 mg. While that is far below the 400 mg daily threshold, it can be enough to delay sleep onset or reduce deep sleep in caffeine-sensitive individuals. The caffeine half-life calculator lets you model the decay for your own weight and timing, and the latest cup before bedtime tool helps identify a personal cutoff hour.

A 47 mg cup of Earl Grey consumes 12% of the 400 mg daily limit recommended by the FDA for healthy adults. That means you could theoretically drink about 8.5 cups over the course of a day before hitting the ceiling, though spacing them evenly matters because a single dose of 200 mg is considered the safe upper limit for a single intake by the European Food Safety Authority (EFSA, 2015). For pregnant individuals, the EFSA advises limiting total daily caffeine to 200 mg, so no more than 4 cups of Earl Grey per day. Adolescents, according to the same EFSA opinion, should stay below 3 mg per kg of body weight, which for a 50 kg teenager works out to 150 mg—about 3 cups. Children are more sensitive, and health authorities generally recommend minimal or no caffeine for those under 12.

Sleep disruption is a separate concern. The half-life model shows that a 47 mg dose at 15:00 leaves 23 mg at 21:00 and 16 mg at midnight. While Drake et al. (2013) demonstrated that 400 mg taken six hours before bedtime still reduced total sleep time by over an hour, a 47 mg dose is an order of magnitude smaller. For most people, an afternoon Earl Grey is unlikely to cause noticeable sleep loss. However, if you are particularly sensitive or aiming for zero caffeine in your system by 23:00, the latest cup before bedtime calculator suggests finishing your last Earl Grey no later than 11:00, based on the 5.7-hour half-life and a target of less than 10 mg at lights-out. Individual metabolism varies; some people clear caffeine twice as fast, others half as fast, so these numbers are starting points, not guarantees.

Within the tea family, Earl Grey’s 47 mg per 240 ml makes it a standard black tea. It matches black tea exactly and sits just below English Breakfast (50 mg). Compared with other tea types, it has 68% more caffeine than green tea (28 mg), 27% more than oolong (37 mg), and nearly three times the caffeine of white tea (16 mg). It is substantially lower than matcha (70 mg), where the whole powdered leaf is consumed, and less than yerba mate (85 mg), which comes from a different plant altogether. A chai latte (50 mg) delivers a nearly identical dose, while bottled iced tea (45 mg per 355 ml) is slightly weaker per volume.

When the comparison shifts to coffee, the difference is clear: a 240 ml drip coffee delivers 96 mg, so Earl Grey provides exactly half the stimulant load. A single 30 ml espresso shot (63 mg) contains 34% more caffeine than a full cup of Earl Grey. Among packaged drinks, a 250 ml can of Red Bull (80 mg) has 70% more caffeine, and a 473 ml Monster Energy (160 mg) more than triples it. For someone accustomed to coffee, switching to Earl Grey cuts caffeine intake by roughly 50% per serving, which can be a practical step for reducing overall consumption without eliminating the morning ritual. The side-by-side drink comparison tool lets you stack any two beverages from our dataset to see the numbers directly.

What changes the number for Earl Grey tea

The 47 mg figure is a representative value for a 240 ml cup of Earl Grey brewed from black tea leaves with a typical 3-minute steep. Several factors can push the actual caffeine content higher or lower. Steeping time is the most influential variable under the drinker’s control: a 1-minute infusion may extract only 20–30 mg, while a 5-minute steep can reach 60–70 mg, according to extraction studies compiled by the USDA FoodData Central. Water temperature matters too; boiling water (100 °C) extracts caffeine more efficiently than water at 80 °C, though the difference is smaller than the effect of time.

Tea leaf size and grade also introduce variation. Broken leaf grades, common in tea bags, expose more surface area and tend to release caffeine faster than whole leaf teas. The bergamot oil that defines Earl Grey does not affect caffeine content, so the caffeine level is determined entirely by the black tea base. Different brands blend different black teas—some use a stronger Assam, others a milder Ceylon—which can shift the caffeine by 10–15% in either direction. Our dataset uses the USDA average for black tea, which is why Earl Grey and plain black tea both register 47 mg per 240 ml.

Decaffeinated Earl Grey is widely available. The decaffeination process removes most but not all caffeine; a 240 ml cup of decaf Earl Grey typically contains 2–5 mg, roughly 90–95% less than the regular version. If you are strictly avoiding caffeine, the only zero-caffeine option in the tea category is herbal tea, which is made from plants that never contained caffeine to begin with. Serving size also scales the dose linearly: a 360 ml (12 fl oz) mug contains about 71 mg, and a 480 ml (16 fl oz) travel tumbler about 94 mg, approaching the strength of a full cup of coffee.

Where this figure comes from

The 47 mg value for Earl Grey tea is drawn from the USDA FoodData Central database, which reports an average of 47 mg of caffeine per 240 ml (8 fl oz) of brewed black tea. Because Earl Grey is a flavored black tea and the bergamot oil does not alter caffeine content, we apply the black tea average directly. The USDA figure is itself a composite of multiple laboratory analyses of commercially available tea bags and loose leaf teas brewed under standardized conditions. You can explore the underlying data and see how it compares with other drinks in our open caffeine dataset.

Published caffeine values for tea vary widely—from 14 mg to 61 mg per cup in some reviews—because of differences in tea variety, growing conditions, manufacturing, and brewing method. We chose the USDA central estimate because it is transparent, reproducible, and widely cited by health authorities. If a new meta-analysis or large-scale testing program produces a robust updated average for black tea, we will revise this page accordingly. The goal is to give you a single, defensible number that reflects what you are most likely to encounter when you brew a typical Earl Grey at home or order one at a café.

Bottom line

A standard 240 ml cup of Earl Grey tea contains 47 mg of caffeine, which is 19.6 mg per 100 ml and exactly half the caffeine of a same-sized drip coffee. That single serving represents 12% of the 400 mg daily limit for healthy adults. After drinking, the caffeine decays with a half-life of 5.7 hours, leaving about 23 mg after 6 hours and 11 mg after 12 hours. For most people, an afternoon Earl Grey provides a moderate, sustained lift without the intensity of coffee, but those watching their sleep or total intake should count it as a meaningful source of caffeine.

If you are comparing options, Earl Grey sits in the middle of the tea spectrum—stronger than green or white tea, weaker than matcha or yerba mate, and far below any coffee or energy drink. Use the tools on this page to model your own caffeine clearance and find your personal cutoff time. All figures are estimates based on population averages; your actual response may differ.