A 12-ounce (355 ml) can of Coca-Cola contains approximately 33 to 34 mg of caffeine

. This amount is considerably lower than the caffeine content in a similar- sized cup of coffee, which typically contains about 95 mg or more caffeine

. Diet Coke has a higher caffeine content, with about 42 to 46 mg per 12-ounce can

. In summary:

• Regular Coke (12 oz): ~33-34 mg caffeine
• Diet Coke (12 oz): ~42-46 mg caffeine

This caffeine level is modest compared to coffee and many energy drinks, making Coke a relatively low-caffeine beverage option