How Much Caffeine Is in Tea? By Type and Brew Time

Caffeine in tea varies enormously, and the biggest variable is not the type of tea but how you brew it. A strong cup of green tea can contain more caffeine than a weak cup of black tea, because caffeine extraction depends on leaf quantity, water temperature and steeping time far more than on the category. As a rough guide, an average cup of tea contains roughly 20 to 60 milligrams of caffeine, depending on strength, against roughly 80 to 100 milligrams for an average cup of brewed coffee. The widely repeated claim that black tea is always stronger than green is not reliable.

Why tea type explains less than people think

All true tea comes from Camellia sinensis, and the caffeine is in the leaf before processing. Processing — oxidation, firing, roasting, fermentation — changes flavour compounds far more than it changes caffeine. What does change is how readily the caffeine comes out.

Leaf grade matters. Small, broken leaf extracts faster, which is why a tea bag can deliver a high dose quickly. Whole leaf extracts more slowly, so a whole-leaf tea steeped for two minutes may contain less caffeine in the cup than a tea bag steeped for five, even though both start from similar leaf.

Realistic ranges by category

Published figures vary widely between sources, and this is worth stating plainly rather than quoting a false precision. The ranges below reflect typical commercial teas brewed in ordinary ways, not laboratory maximums.

Matcha deserves a note because it breaks the usual rule. With steeped tea you discard the leaf, so you extract only part of the caffeine. With matcha you drink the leaf, so you get all of it. This is why a small bowl of matcha can contain more caffeine than a large mug of green tea.

Why tea feels different from coffee

People often report that tea caffeine feels gentler than coffee caffeine at a similar dose. Tea contains L-theanine, an amino acid that appears to modify the subjective effect of caffeine, and this is a reasonable explanation for the difference in how the two drinks feel. It is also frequently overstated in marketing. The effect is real but modest, and a strong cup of tea will still keep you awake.

How to reduce caffeine without giving up tea

• Brew cooler and shorter. This is the most effective single change.
• Use less leaf. Halving the leaf roughly halves the caffeine.
• Choose whole leaf over dust. The same cup has less caffeine and more flavour.
• Discard the first infusion. Some caffeine is removed, though the popular claim that 80% is removed in 30 seconds is exaggerated.
• Drink the second and third infusions rather than loading up the first. Caffeine continues to extract, but total intake across a session can still be lower than several strong first infusions.
• Choose a different plant: rooibos, honeybush and most herbal infusions contain no caffeine at all.

Decaffeinated tea is not caffeine-free

Decaffeinated tea has had most, but not all, of its caffeine removed — typically leaving a small percentage. If you are avoiding caffeine for medical reasons, check the specific product rather than assuming zero. The decaffeination process also removes some flavour compounds, which is why decaffeinated tea often tastes flatter than the same tea with caffeine.

Frequently asked questions

Working out your own cup

Published caffeine figures are averages, and your cup is not an average. If you want a realistic number for what you actually drink, fix your variables and compare against how you feel rather than against a table.

• Weigh your leaf once. An unweighed teaspoon varies by a factor of two depending on the tea, which matters more than any category difference.
• Note the water temperature and time. These two decide most of the caffeine in the cup.
• Drink the same setup three days running and notice when you feel alert and when you feel jittery.
• Change one variable at a time. Halving the leaf is the most effective single adjustment.

Someone who feels nothing from three cups of strong black tea and someone who cannot sleep after a green tea at four in the afternoon are both normal. Individual caffeine metabolism varies substantially and is largely genetic. The category you choose matters less than the dose you brew.

Tea versus coffee: a fair comparison

The gentler reputation of tea is partly L-theanine, an amino acid that appears to modify the subjective effect of caffeine, and partly the delivery pattern. A gongfu session spreads intake across an hour; an espresso delivers it at once. Both are real effects and both are routinely overstated in marketing. A strong cup of tea will still keep you awake.

If you are cutting caffeine for medical reasons

This is where general guidance stops being useful. Caffeine restrictions are set individually, particularly in pregnancy and for specific cardiac or neurological conditions, and the relevant limit is the one your clinician gives you.

What is useful is knowing that tea counts toward the total alongside coffee, chocolate, cola and some medications, and that decaffeinated tea is not caffeine-free. If you need to cut caffeine substantially, the reliable route is a different plant: rooibos, honeybush, mint and chamomile contain none. Our guide to who should moderate tea sets out the other cautions that apply alongside caffeine.

Frequently asked questions