By law, the labels on containers of distilled spirits and wine must show either alcohol by volume (ABV) or proof. Here is what those two measurements mean. (Beer labels aren't required to provide this information.)

  • Percent ABV = percent alcohol by volume, which is the percentage of the liquid that is pure alcohol

  • Proof = two times ABV

So 40 percent ABV = 80 proof.

The Dietary Guidelines for Americans, written by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, defines moderate drinking as two drinks a day for a man, one drink a day for a woman. But how much alcohol should that one drink contain?

When these two U.S. government regulators say "one drink," this is what theey mean:

  • 1.5 ounces distilled spirits (80 proof)

    This is the amount of liquid held by a standard shot glass.

  • 5 ounces wine

  • 12 ounces (regular) beer