You can order the same drink at bars all over the world, but how much booze each order is really going to get you depends a lot on where you are. A new study out today in the journal Addiction surveyed the different alcohol contents of a single drink in 75 different countries. What they found was that the alcohol content of "one drink" varies wildly depending on where you order it.
In Iceland, for example, a single drink came in with a trim 8 grams of pure ethanol; meaning that you could be two Icelandic drinks in with one more on the way to hit the equivalent of a single Austrian drink, which had 20 grams. A drink in the United States, though, would dissatisfy Icelanders and Austrians both to the exact same degree -- it fell right in the middle at 14 grams of pure ethanol. An Australian drink contains 10 grams of ethanol, which puts it around average.
Here's the full chart of how each country surveyed counted a single drink:
The actual sizes, though, are probably even more all over the place than the numbers you see above. Why?
Because the study used government standards for a single drink. The actual drinks you get poured out at a bar, though, are just approximations; and some places are going to be either much heavier or lighter-handed. Perhaps that's one reason several countries chose to go for a range or an approximate size, rather than a single standard number and other surveyed countries chose not to set any standard at all.
For those that wish there was a little more consistency in the measure, the WHO has settled on what it thinks a single drink is: Anything with 10 grams of pure ethanol in it. But with populaces all over the world who are all used to receiving what they think of as a standard pour, the meaning of "one drink" is likely to keep on depending on where you are when you order it.