Consumer Reports today published a report on the level of caffeine in popular energy drinks. Their findings suggest that many of the energy drinks Americans consume on a daily basis have wildly varying levels of caffeine, and in some cases have more than anyone might suspect.

Consumer Reports purchased 27 popular energy drinks from stores in Connecticut, New York, and New Jersey. It tested three lots of each beverage for the caffeine, sugars, and calories found in one serving of the beverage. An average 8-ounce cup of coffee has around 100mg. of caffeine.

Topping the list is 5-hour Energy Extra Strength, which has an incredible 242mg. of caffeine in just 1.9fl. oz. of liquid. Following that is Rosckstar Energy Shot with 229mg. of caffeine and NOS High Performance with 224mg, though that is a 16fl. oz. beverage.

Monster Beverage’s Monster X-presso placed fourth highest on the list with 221mg. of caffeine in 6.8fl. oz. of liquid. Regular Monster Energy drinks showed up near the middle of the chart, with 92mg. of caffeine in 8fl. oz. of liquid. This may seem surprising, since Monster Beverage has recently come under fire for the high caffeine content of its drinks.

Just this week, the family of a 14-year-old girl who died of caffeine toxicity sued Monster Beverage over the death. The lawsuit alleges that the girl consumed two 24fl. oz. cans of Monster Energy drinks in under 24 hours shortly before dying. Going by Consumer Reports’ measurements, that works out to 552mg. of caffeine the girl consumed. Consumer Reports states that “data suggests” healthy adults can consume up to 400mg. of caffeine per day, while children can handle up to 45mg. or 85mg., depending on their weight.

Oddly enough, a 5-hour Energy drink, the company’s “decaf” shot, also placed as having the least caffeine content of the drinks tested with only 6mg. of caffeine. Red Bull, perhaps the most well-known energy drink in U.S. markets, placed near the middle of the pack with 83mg. of caffeine.