A brewed cup and a green tea extract capsule both get discussed as “EGCG,” and they are not the same exposure. An 8 fl oz brew is often around 30 mg of EGCG, commonly somewhere between 25 and 50 mg depending on the leaf and the steep. A 2 gram teaspoon of matcha is higher, around 60 mg in this estimate, because you drink the leaf instead of throwing it out. Extract labels sometimes list 200 mg or more in one capsule.
Enter cups, matcha teaspoons, and the EGCG number printed on the product, times the number of capsules. The page adds the drink side and says how many of these standard cups sit near the label dose. That comparison is there so a capsule does not look like “one strong cup.” It is not a suggestion to match the capsule by drinking that many cups, and it is not a suggestion to take the extract.
Concentrated catechins have been linked to liver injury in some people, especially at high labeled doses and when taken on an empty stomach. Brewed tea and an extract are different products. The green tea extract guide covers what research supports and what it does not.
A brewed 8 fl oz cup is counted as about 30 mg EGCG, with a real-world band nearer 25–50 mg. A 2 gram teaspoon of matcha is counted as about 60 mg because you consume the leaf. The extract side is whatever EGCG milligrams the label states, times the number of capsules. The page then says how many of those cups sit near one label dose.
EGCG varies with leaf, water temperature, and time. Extracts are not just strong tea: concentrated catechins have been tied to liver injury in some people, especially at high labeled doses. This comparison is not a suggestion to match a capsule with cups.
A usual 8 fl oz brew is often around 30 mg, commonly somewhere between 25 and 50 mg. The calculator uses 30 mg so cups and labels can be compared on one scale.
A tea bag steeps leaves and you throw them out. Matcha is ground leaf whisked into the cup, so you ingest more of what was in the leaf. A 2 gram teaspoon is the figure used here.
The math can show that a labeled extract dose is several cups, not one. That is not advice to take the extract, or to drink that many cups for a medical reason. Extracts and brewed tea are not interchangeable products.