You know not to drink and drive. The DMV sends you a chart every year. Here it is:
There is no safe way to drive while under the influence. Even one drink can make you an unsafe driver. Drinking alcohol affects your BLOOD ALCOHOL CONCENTRATION (BAC). It is illegal to drive with a BAC of .08% or more (.04% or more if you drive commercial vehicles; .01% or more if under 21). However, a BAC below .08% does not mean that it is safe or legal to drive. The charts below show the BAC zones for various numbers of drinks and time periods. Remember: One drink is a 1-ounce shot of 80-proof liquor (even if mixed with non-alcoholic drinks), a 5-ounce glass of 12% wine, or a 12-ounce glass of 5% beer. These one drink equivalents change if you are drinking ale, malt liquors, fortified wines, port, brandy, different proof liquor, or if you are drinking on an empty stomach, are tired, sick, upset, or have taken medicines or drugs.HOW TO USE THESE CHARTS: Find your weight chart. Then, look for the total number of drinks you have had and compare that to the time shown. If your BAC level is in the blue zone, your chances of having an accident are 5 times higher than if you had no drinks, and 25 times higher if your BAC level falls in the black zone. See the CA DMV site here.