When you're enjoying a refreshing mojito, it can sometimes be hard to tell how much alcohol you're actually taking in. The sugar, lime juice, mint and sparkling water in the drink can disguise the flavor of the rum, or at least make it less noticeable. As with any drink, the level of alcohol in a mojito can vary, but it's typically between 10 percent and 15 percent of the drink's volume.
Calculating Alcohol Level
To determine the alcohol level of a mixed drink like a mojito, simply multiply the alcohol content by the percentage of liquor in the drink. For instance, if a mojito is made up of equal parts lime juice, water or club soda and rum, then 1/3 of the drink is rum. Multiply this number by the alcohol content of the rum -- usually 40 percent alcohol by volume, although it can vary -- and you get 13.3 percent.
Like all classic mixed drinks, the mojito isn't produced according to a specific formula. Different bartenders will combine ingredients in different proportions. For instance, BBC Food's mojito recipe calls for only a splash of soda water, producing a mojito that's more like sugared rum served over ice with lime and mint. A mixture like this will have a much higher alcohol by volume. However, high-alcohol mojitos like this are comparatively rare.
Buying Mixed Mojitos
Although a fresh mojito usually tastes best, you can also buy bottled, pre-mixed mojitos, which tend to be 10 to 15 percent alcohol. For instance, you can purchase a bottled mojito that has 15 percent alcohol by volume. This is a typical alcohol level not only for a mojito, but for many mixed drinks, which often have roughly the same amount of alcohol as a glass of wine.
Lower Alcohol Alternatives
If you don't want to overdo it, some lower-alcohol mojito alternatives are available. Bartenders in Utah have developed an alternative mojito that replaces the rum with chilled sauvignon blanc. The result maintains the fresh, minty mojito flavor but with a fraction of the alcohol content. Visitors to southern Utah sometimes choose this drink so as to avoid hiking with a hangover.