Blood Alcohol Level (BAL) The amount of alcohol in your blood stream is referred to as Blood Alcohol Level (BAL). It is recorded in milligrams of alcohol per 100 milliliters of blood, or milligrams percent. For example, a BAL of .10 means that 1/10 of 1 percent (or 1/1000) of your total blood content is alcohol. When you drink alcohol it goes directly from the stomach into the blood stream. This is why you typically feel the effects of alcohol quite quickly, especially if you haven't eaten for a while. BAL depends on: 1. Amount of blood (which will increase with weight) and 2. The amount of alcohol you consume over time (the faster you drink, the higher your BAL, as the liver can onl