3 beers is enough for a DUI and even 2 beers can be enough to get a DUI depending on how far apart the beers were consumed and your weight.
1 beer will show up on a breathalyzer although it won't usually put you over the limit and usually will not result in a DUI arrest.
Having 2 beers can put you over the BAC limit and can result in a DUI arrest and charge.
In general, 1 average beer or most other alcohol will not put a driver over the limit of . 08% blood alcohol concentration (BAC).
2 regular beers or other alcohol drinks can be enough to put you over the BAC limit if you weigh less than 120 pounds.
The ratio of lean body mass is what makes all the difference.
Most experts believe that it takes about 3 drinks (12 oz beer, 5 oz glass of wine, or a shot of liquor) taken within an hour for a 100 lb person to reach . 08% BAC.
A breathalyzer can first detect alcohol in a person's system about 15 minutes after the alcohol has been consumed and up to 24 hours later.
If you want to stay under a BAC of 0.08, the general rule is that you should not drink more than one standard alcoholic drink an hour, but this rule comes with many catches.
If your blood alcohol content (BAC) is 0.08% or higher, you're legally impaired and you can be arrested for suspicion of driving under the influence (DUI).