One 12-ounce can of Coca-Cola contains 34 milligrams of caffeine. Flavored versions of regular Coca-Cola, including Cherry Coke and Vanilla Coke, have the same caffeine content as the original version. Diet Coke has a higher caffeine content than other Coca-Cola beverages, containing 45.6 milligrams of caffeine.
Cola drinks from other companies contain similar amounts of caffeine to Coca-Cola. Pepsi contains 37.5 milligrams of caffeine, while Diet Pepsi has a slightly lower caffeine content at 36 milligrams of caffeine per 12-ounce can. These soft drinks contain less caffeine than brewed coffee, energy drinks or black tea, but more caffeine than green tea.