How much can I drink and still drive safely (and legally)?

I feel like most people are raised under the excessively naive belief that “There is no safe way to drive while under the influence. Even one drink can make you an unsafe driver.” There’s probably several good reasons for this: unsupervised teen socializing, suburban sprawl, and an unrealistic legal drinking age, but I digress.

The quote above comes from the top of the Alcohol Impairment Chart that came with my license renewal today. But for whatever reason, the California DMV didn’t stop there. They included a series of charts for seven weight ranges that factor in the number of drinks consumed and the number of hours since your first drink. Find the right point on the chart and you’ve got a pretty good idea of what your blood alcohol concentration (BAC) will be.

What I like about this approach is that it’s honest and informative, rather than FUD. And my first thought was, “I’ve gotta turn this into HTML.” So I did.

Select your weight range:

Time from
1st Drink
Total Drinks
1 2 3 4 5 6 7 8
1 hr                
2 hrs                
3 hrs                
4 hrs                
(.01%–.04%) Possible DUI
(.05%–.07%) Likely DUI
(.08% and up) Definitely DUI

The California DMV says, “[This chart has] been constructed so that fewer than 5 persons in 100 will exceed these limits when drinking the stated amounts on an empty stomach.”

“One drink” is a 1 ½-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.

For more info, click here.

Feel free to if you found this useful.


I am familar with this chart, as it indicates that consuming one drink makes it likely that it would be illegal for me to drive. breaking the law!


While I applaud all efforts to ensure safer roads, anywhere. I’m not sure what the law is in CA or the US in general. But in NZ, cannibis is illegal, however if one is stoned – and driving there is no test that’s applied.

Just seems an odd way to apply law.


nifty chart. i’ve read about the differences in how women’s bodies process alcohol vs. men’s bodies due to the presence of an enzyme called alcohol dehydrogenase. most guys have more of it than most girls, and it breaks down the alcohol in the stomach, so that, for most guys, less of the alcohol from a drink actually makes it into the bloodstream. which is a double-edged sword, I guess. More expensive date, but, can probably drive home?

If you are of Irish descent your “Weight Range” for the select list should be 130% your actual weight. The Irish are genetically predisposed to mass alcohol consumption.

The same rule applies if you’re Italian or French, but only if you stick to drinking wine.

Quit trying to rationalize your raging alcoholism with your fancy chart!

Sweet chart. Good to know.


i though that drinking and driving was totally illegal.

Me and my partner are doing a project on drinkin and driving and this chart helps so much..

My partner and I Are really impressed with your chart its amazing..


but doesn’t it depend on what kind of drink you’re getting since different drinks have different alcohol levels?

bringtherain, “one drink” is always relative to the type of alcohol you are drinking. I’ve updated the links to the CA DMV Alcohol Impairment Chart (which had changed) and excerpted their definition of one drink:

“One drink” is a 1 ½-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.


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