The standard definition of a single shot of alcohol varies worldwide, with measures ranging from 30 to 60 milliliters. As such, where a person is in the world determines how many shots can be poured from a 1-liter bottle.
In the United States, a shot is defined as 1.5 ounces, which is 44 milliliters; this allows for 22 full shots for a 1-liter bottle. Countries in the Baltic region typically serve shots that are 50 milliliters, which allows for 20 shots per 1-liter bottle. Shot glasses tend to come in a wide variety of sizes, generally much larger than the standard size of a shot of liquor so they do not brim over when served.