Question: how much is 40 mg of caffeine?
Answer: For reference, a 12 ounce can of a caffeinated soft drink typically contains 30 to 40 milligrams of caffeine, an 8-ounce cup of green or black tea 30-50 milligrams, and an 8-ounce cup of coffee closer to 80 to 100 milligrams. Caffeine in energy drinks can range from 40-250 mg per 8 fluid ounces.