how much caffeine does green tea have

An 8-ounce (about 230 ml) cup of green tea contains approximately 30 to 50 milligrams of caffeine. The caffeine content can vary depending on the type of green tea, how it is grown, processed, and brewed. For example, powdered green teas like matcha tend to have higher caffeine content (around 60-70 mg per 8 oz) compared to bagged or loose leaf green tea. The caffeine in green tea is generally less than that found in black tea, coffee, and many energy drinks, providing a milder stimulant effect often combined with the calming amino acid L-theanine.