Caffeine Content of Tea (Green)
An 8 ounce cup of Green Tea contains 25 milligrams of caffeine.
It is very difficult to put an exact figure on Green Tea caffeine. Like other drinks from cultivated plants (tea, coffee), there are numerous variables that can alter caffeine content.
Length of brewing time also affects caffeine content - the longer the brew - the higher the caffeine.
One study compared the content of dry matter from tea leaves and found Green Tea had 10-20mg per 1 gram dried matter. Black Tea had 22-28mg per 1 gram dried matter.
So as a general rule, Green Tea has less caffeine than Black Tea.
Another study (here) showed that Green Tea (in Japan) has 30mg caffeine per 200ml cup.
The figure we have included in our caffeine database is an average of these two.
Tea makers Lipton list a figure of 45mg caffeine for their 100% Green Tea drink. They claim this is from 1 to 2.5 minutes of brewing (see source below)
Where To Buy Green Tea
How Does It Compare With Other Drinks?
Tea (Green) contains 3.12 mgs of caffeine per fluid ounce (10.57mg/100mls).
Caffeine per Ounce
Caffeine per Item
How Does It Compare With Other Foods?
Caffeine per Item
Sources
1. Khokhar S, Magnusdottir SG. Total phenol, catechin, and caffeine contents of teas commonly consumed in the United kingdom. J Agric Food Chem. 2002 Jan 30;50(3):565-70. Caffeine in Lipton drinks (link).
