We hear a lot about alcohol and health. Some studies say a little bit of booze might be good for the heart. Others disagree, noting flaws in the way these studies were conducted. In any case, drinking can be a delicate titration—too little and you might be missing out on a health benefit. But too much alcohol not only feels terrible the next day, it can also be really, really dangerous.

The problem, though, is that alcohol quantities can be challenging to figure out. You might know your limit is two glasses of wine, but what size are the glasses? And how strong is that wine?

For researchers, the fact that people don’t know how much they’re drinking is one