Texas Drunk Driving Attorneys: Calculating Your BAC


In Texas, it is illegal to drive with a blood-alcohol content (BAC) of .08 or higher. For younger drivers under the legal drinking age, zero-tolerance rules impose penalties with a BAC of .02 or higher. Commercial drivers also have a lower maximum BAC and can face consequences if their blood alcohol content exceeds .04. In addition to these general rules, Texas also imposes enhanced penalties upon any driver with a blood-alcohol content level of .15 or higher.

Because your BAC is such an important determining factor under Texas DWI law, it is important to have some idea of how many drinks will cause you to exceed the legal limit. The way in which alcohol affects your blood-alcohol content can vary based on a number of different factors including your weight, how long the alcohol metabolizes in your body, your metabolism and your gender. Medications that you take can also affect the way in which your body processes alcohol.

Even a simple choice about whether to mix a drink with diet soda or regular soda can affect your BAC. A recent study found that diet soda mixed with vodka resulted in breath alcohol concentrations that were 18 percent higher after 40 minutes, compared to people who drank a regular soda mixed with the same amount of vodka.

For all of these reasons, it can be difficult to get an accurate estimate of how much you can drink before you are over the legal limit. Despite the challenges, however, our Texas DWI lawyers believe that it is important that you have some idea of how drinking will affect you and of how much is too much to drink.

Estimating your Blood Alcohol Content

Because different types of drinks have differing amounts of alcohol in them, it is important to first understand the alcohol content of varying types of drinks. For example:

  • One ounce of 80 proof spirits is generally considered to constitute one drink.
  • A three ounce glass of wine has an ounce of eighty proof spirits and is considered one drink.
  • An eight ounce glass of five percent beer has an ounce of eighty proof spirits and is considered one drink

Using this information, the National Council for DUI Defense provides a table that allows you to estimate your BAC based on the number of drinks consumed, your weight and your gender. The table is available on its website and reveals, for example, that:

  • A 100 pound man who has two drinks over the course of one hour would likely be at the legal limit of .08.
  • A 200 pound man who has five drinks in an hour would likely be at the legal limit of .08.
  • A 100 pound woman who had two drinks in an hour would be over the limit with a BAC of .09.
  • A 200 pound woman who had four drinks in an hour would be slightly over the limit with a BAC of .09.
By using this table, you can estimate how drinking alcohol will affect your BAC, and you can get a rough idea of how many drinks you can consume before you are too drunk to drive.
The website for Joseph LaBella & Associates also has a “BAC calculator.” Click here to go to the home page, scroll to the bottom and click on the calculator.
Remember, drinking while intoxicated is extremely dangerous, and you are at risk of both arrest and of causing an auto accident if you drive drunk. It is always best to err on the side of caution and have either nothing to drink or stick to one drink if you plan to drive.  While estimating your BAC can be helpful, therefore, you should not count on estimates to always be accurate for you, and you should pay attention to your own limits when making the decision to drive after having anything to drink at all.
You need an experienced, aggressive Texas DWI lawyer.  Call 1-800-395-5951 today for your free consultation. More than 20 years experience.

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