The BAC is the abbreviation of the blood alcohol content and refers to the concentration of alcohol in the bloodstream, which is usually used for the medical or legal purpose. Blood alcohol content is usually expressed as mass per volume in the percentage. Different countries have different standards of the legal rules about the BAC. For people's convenience, there are some BAC chart to help estimate and compare the blood alcohol levels, for example BAC Chart and Alcohol Impairment Chart. If you are interested in these charts, you can visit our website and download them for free.