How Much Caffeine Is in Black Tea?

Caffeine in black tea, in summary: How much caffeine is in black tea: the 40 to 70mg range, what moves the number, how it compares to coffee, decaf, and sensible budgeting.

Black tea is the caffeinated workhorse of the British cup, and "how much caffeine is in it" is one of the most asked questions in tea. The clear answer is a range, not a number, and you control most of it. It belongs to the caffeine group of pages, alongside the ultimate caffeine guide and the black tea guide.

Last reviewed by the teas.co.uk team in April 2026.

The clear range

A typical mug of black tea lands roughly in the region of 40 to 75 mg of caffeine, with strong, long steeped builders style brews at the top of that and weak, quick ones well below it. That is lower than a typical mug of brewed coffee and higher than most green tea as commonly brewed, but the ranges overlap, which is the point this cluster keeps making.

What moves the number

Leaf quantity and steep time are the big levers: a strong four minute brew with plenty of leaf is at the top of the range, a quick two minute one well down it. Fully boiling water (correct for black tea) extracts efficiently, see the water temperature guide. CTC and broken leaf bagged black extracts fast and can hit harder per minute than whole leaf, the orthodox versus CTC point from the Assam region.

How it compares

Black tea versus coffee, green and matcha is covered in tea vs coffee caffeine and matcha vs green tea caffeine. Roughly: coffee strongest, then a strong matcha, then strong black, then green, then white, then caffeine free herbal, but brewing blurs every boundary.

Decaf black tea

Decaffeinated black tea is low caffeine, not zero, typically a small fraction of the original, the distinction made in decaf vs caffeine free and the process in how caffeine is removed. For no caffeine at all you need a herbal or rooibos, see the low caffeine list.

Practical budgeting

At roughly 40 to 75 mg a mug, several cups of black tea fit comfortably under a normal daily ceiling, and well within the lower pregnancy limit if moderated, see is black tea safe in pregnancy. If it is keeping you up or making you jittery, brew it weaker, smaller and earlier, see tea before bed and why tea makes you feel sick.

The bottom line

Black tea is moderately caffeinated, less than coffee, more than most green, and the cup is in your hands: leaf, time and size set the dose. Treat the number as a controllable range, not a fixed fact, the throughline of this whole cluster.

Black tea caffeine, at a glance

Cup	Caffeine per 200ml
Standard British black	~45 to 55mg
Strong Assam, stewed	~60 to 70mg
Lighter Ceylon / Darjeeling	~30 to 45mg
Decaf black	~2 to 5mg
Filter coffee (for comparison)	~80 to 100mg
Green tea (for comparison)	~30 to 40mg

Why the number moves, and a myth to drop

The figure is a range because you drink the extraction, not the leaf. Most of the caffeine is out in the first thirty seconds and roughly ninety five per cent by four minutes, so extra steeping mainly adds tannin, not caffeine; an unattended five minute brew is where most accidental overshoot comes from. Cup size matters too: a large takeaway mug simply holds more liquid, and more caffeine, than the small teacup most quoted figures assume. One myth worth dropping is that oxidation creates caffeine, so black must beat green. It does not. The amount is set in the living leaf by cultivar, age and growing conditions, with assamica carrying more than Chinese sinensis, so a high grown, fine plucked black can sit below a coarse green. What black reliably does is extract efficiently, boiling water plus broken leaf or CTC bags, which is why a builder's mug hits harder. The L theanine that comes with tea, largely absent from coffee, softens the same caffeine into a smoother, alert focus.

Want to actually buy a good one?

If black tea is what you drink every day, a good blend does beat a tired supermarket one. The black teas listed below were chosen for this exact question, so begin with them. To see the wider range, browse black tea at teas.co.uk or the full tea shop. With black tea, go by a fair description and the price per cup instead of the claims on the box, and UK delivery is free over £35.

Browse the clear tea range

Reference noted

For everyday teas relevant to this topic: English Breakfast, Earl Grey, green tea, loose leaf tea, Darjeeling, oolong, and herbal tea. Browse the wider tea range, and above £35 UK shipping costs nothing.

From the curatorteas · Drink the black tea you like at the strength you like, whatever the shelf recommends. Curiosity is the only reliable guide.