Question: how many milligrams of caffeine in a cup of green tea?
Answer: An 8-ounce (230-ml) cup of green tea contains between 30 and 50 mg of caffeine. The recommended maximum amount of caffeine per day is 400 mg, which is the equivalent to around 8 cups of green tea. However, it's best that you don't drink 8 cups at one time, especially if you are sensitive to caffeine.