How much caffeine is in black tea? About 47 mg in an 8 oz cup of brewed black tea, based on USDA FoodData Central. That's about half the 95 mg in an 8 oz cup of brewed coffee. Real cups vary: when researchers tested 20 brewed teas, they found 14 to 61 mg per serving, and steep time mattered more than the type of tea.
So one cup of black tea is a moderate dose, and two cups come to about one coffee. To see what your own cups leave in you at bedtime, use the caffeine calculator.
Free toolCaffeine Cutoff CalculatorHow much caffeine is still in you at bedtime, and your latest cup.How much caffeine is in a cup of black tea?
An 8 oz cup of brewed black tea has about 47 mg of caffeine. USDA lists brewed black tea at 20 mg per 100 grams, and weighs an 8 oz cup at 237 grams.
| Brewed black tea | Caffeine |
|---|---|
| 6 oz cup | about 36 mg |
| 8 oz cup | about 47 mg |
| 12 oz mug | about 71 mg |
| 16 oz mug | about 95 mg |
| Decaf black tea, 8 oz | about 2 mg |
A big 16 oz travel mug of black tea has about as much caffeine as an 8 oz coffee. Lab tests of decaf teas found less than 12 mg per serving, so decaf is low but not always zero.
How much caffeine is in a black tea bag?
One black tea bag steeped in an 8 oz mug usually gives roughly 30 to 50 mg, about 47 mg on average. The bag holds more caffeine than ends up in your cup. How much comes out depends mostly on how you brew it.
What raises the caffeine from one bag:
- Longer steeping. In the brewed-tea study, steep time changed the caffeine in the cup, while cup size (6 vs 8 oz) mostly didn't change the amount per ounce.
- Squeezing or leaving the bag in. A bag left in the mug keeps extracting.
- Two bags in one mug. That roughly doubles the dose.
The study didn't publish a simple minutes-to-milligrams chart, so we don't give one here. If you want a gentler evening cup, a short steep is the easy lever.
Black tea vs coffee: which has more caffeine?
Coffee, by about two to one. An 8 oz cup of brewed coffee has about 95 mg, and an 8 oz cup of black tea about 47 mg. Even the strongest brewed teas in the lab study, at 61 mg, came in under a standard cup of coffee.
| 8 oz cup | Caffeine |
|---|---|
| Brewed coffee | about 95 mg |
| Black tea | about 47 mg |
| Green tea | about 28 mg |
| Decaf black tea | about 2 mg |
| Herbal tea | none |
Our tea vs coffee guide covers matcha, white tea and L-theanine in more detail.
Black tea vs green tea: which has more caffeine?
On average black tea does, about 47 mg vs 28 mg per 8 oz in USDA's data, but you can't count on it cup to cup. USDA lists brewed green tea at 12 mg per 100 grams, compared with 20 mg for black.
In the lab study, white, green and black teas all fell in the same 14 to 61 mg range, with no clear trend by type. A long-steeped green tea can beat a quick-dipped black one. If you're switching to green tea in the afternoon to cut caffeine, keep the steep short too. Does green tea keep you awake covers evening green tea.
How much caffeine is in Lipton black tea?
We don't quote a Lipton figure, because we couldn't verify one on Lipton's own US site. A regular Lipton black tea bag is a standard black tea bag, so the typical 30 to 50 mg per 8 oz cup is a reasonable starting estimate. If the box lists caffeine, go with the box.
Iced and sweet tea are a different story because the glasses are bigger. How much caffeine is in sweet tea has 16 and 32 oz numbers, and chai lattes are covered separately.
What's the latest time to drink black tea before bed?
For an 11 PM bedtime, finish an 8 oz cup of black tea by about 6:27 PM. That's when it falls below 25 mg by bedtime, using the site's average 5-hour caffeine half-life.
| Black tea | Caffeine | Hours before bed | Bedtime 10 PM | Bedtime 11 PM |
|---|---|---|---|---|
| Green tea, 8 oz (for comparison) | about 28 mg | 0 h 49 min | 9:11 PM | 10:11 PM |
| Black tea, 8 oz | about 47 mg | 4 h 33 min | 5:27 PM | 6:27 PM |
| Strong black tea, 61 mg | about 61 mg | 6 h 26 min | 3:34 PM | 4:34 PM |
| Black tea, 16 oz | about 95 mg | 9 h 38 min | 12:22 PM | 1:22 PM |
| Decaf black tea, 8 oz | about 2 mg | already under 25 mg | any time | any time |
What's left at 11 PM from one 8 oz cup (47 mg):
| Cup at | Left at 11 PM |
|---|---|
| 3 PM | 16 mg |
| 5 PM | 20 mg |
| 7 PM | 27 mg |
| 9 PM | 36 mg |
The 25 mg line is a rule of thumb, not an official limit. Some people clear caffeine much more slowly, and pregnancy, some medications and liver problems can stretch it out.
How to keep black tea from costing you sleep
- Have your last regular cup by early evening, about 4.5 hours before bed.
- Steep shorter in the afternoon and take the bag out.
- Switch to decaf black tea or herbal tea after dinner.
- Count refills. Four 8 oz cups is about 190 mg, two cups of coffee's worth.