An 8.2-ounce container of Red Bull has the highest amount of caffeine at 80 milligrams. Other soft drinks containing a large amount of caffeine include Jolt Cola, Pepsi One, Mountain Dew, Mountain Dew Code Red and Diet Mountain Dew.
According to Mayo Clinic, the average healthy adult should ingest no more that 400 milligrams of caffeine per day. Energy drinks like Red Bull are often high in caffeine. By comparison, an 8-ounce cup of drip coffee has between 115 and 175 milligrams of caffeine and brewed coffee has between 80 and 135 milligrams of caffeine. Most regular colas and diet colas, such as Coca-Cola, Diet Coke and Pepsi, average around 40 milligrams of caffeine per 12-ounce serving.