Blood alcohol concentration is a measurement of the amount of alcohol that is in a person’s bloodstream, while breath alcohol concentration is a measurement of the amount of alcohol in a person’s breath.

The term “blood alcohol content” is also referred to as “blood alcohol concentration,” as well as “blood alcohol level.” Additionally, the term “breath alcohol content” is also referred to as “breath alcohol concentration” and “breath alcohol level.” All of these terms are referred to in abbreviated form as “BAC.”

The amount of alcohol in a person’s bloodstream is measured in milligrams (mg) of alcohol per 100 milliliters (ml) of blood. This number is generally expressed as a percentage such as 0.08 or 0.15. If a person has a BAC of .10 percent, that person’s blood supply contains one part alcohol for every 1,000 parts blood. BAC levels are determined through blood testing.

Impairment can also be measured through breath alcohol concentration, which is an approximate measure of blood alcohol concentration. Breath alcohol concentration is measured through a breath analyzer, which is colloquially referred to as a “breathalyzer.”

In a breathalyzer test, the user exhales into the breathalyzer. A series of chemical reactions results in the breath ethanol, which is the intoxicating agent found in alcoholic beverages, being converted into an electric current. The amount of current produced is then displayed on the breathalyzer device as the person’s breath alcohol concentration, which is also expressed as a percentage.

How Many Alcoholic Drinks Until I Am Over The Limit?

The question of how many alcoholic drinks a person can drink until they are “over the limit” generally refers to how many alcoholic drinks it would take for a person to be considered legally drunk. Over the limit varies from state to state, but is usually an 0.08 blood alcohol level.

While there is no exact answer to determine how many drinks it would take for you to reach the legal limit for driving or flying, there is a way to approximate whether you are approaching the legal limit in your state based on:

  • Your weight;
  • How much you have had to drink; and
  • How long you have been drinking.

An example of this would be how if you are around 100 pounds, you can generally only have about one serving of alcohol before being over 0.08. Additionally, you can generally only have two servings before being above 0.1, for those states where the legal limit is 0.1. However, a person who is closer to 160 pounds can have about 3 servings of alcohol and still be below the legal limit for driving. A good baseline is that no matter what your weight is, if you have had three servings of alcohol in rapid succession, you are most likely over the legal limit for blood alcohol level when driving.

Your blood alcohol level will largely depend on how much time you have spent drinking. If you have spaced your drinks out over a lengthy period of time, such as the span of a few hours, your blood alcohol level will be significantly lower than if you had the same amount of drinks in the span of one hour. In general, you can subtract 0.01% from your estimated blood alcohol level for every forty minutes that go by while drinking.

To reiterate, in most states the legal limit for drunk driving is .08%. What this means is that if you are caught driving with a BAC of over .08%, you will likely be charged with a Driving Under the Influence (“DUI”). This can also apply to boating and flying while drunk. Additionally, many jurisdictions enforce a “Zero Tolerance” policy for minors. What this means is that minors cannot have any alcohol at all in their system while driving, even up to 0.01%.

In terms of what constitutes one serving of alcohol, “one drink” can mean:

  • A 12 ounce beer;
  • A 4 ounce glass of wine; or
  • 1 ounce of hard liquor.

What Are Some Other Factors That Could Contribute To A Person’s Blood Alcohol Level?

As previously mentioned, the amount of drinks as well as drinker’s weight and the time between drinks are largely responsible for estimating a person’s blood alcohol level. However, there are some other factors that could contribute to a person’s blood alcohol level as well:

  • Fatigue: Exhaustion can significantly increase a person’s blood alcohol level when they are drinking. It is important to note that even if you have not had much to drink, fatigue can adversely affect your judgment in similar ways as alcohol;
  • Medications: There are some types of medications that can have adverse side effects when taken with alcohol. It is imperative to check the warning labels on any medications that you take, whether prescriptive or over the counter; and
  • Food: Drinking on an empty stomach can increase your blood alcohol level significantly when compared to if you had been eating before or while you were drinking.

What Is A “High BAC” Law? Can I Refuse A Breathalyzer Or Other DUI Test?

A “high BAC” law is a statement of what each state considered to be an acceptable BAC. As previously mentioned, the acceptable limit is generally 0.08%. DUI charges can lead to fines, bad marks on a person’s insurance record, and even jail time. Repeat offenses can result in felony charges in some cases, and some states impose additional measures for drivers who are found with high blood alcohol concentrations. This can be anywhere from .15% to .20%.

The penalties for violating a High BAC law can vary from state to state, but generally result in one or more of the following consequences:

  • Higher criminal fines;
  • Increased jail time;
  • Denial of probation;
  • Required installation of an ignition interlock device on the offender’s vehicle; and
  • Not being allowed to plead guilty in exchange for lesser charges.

Additionally, if the DUI incident caused serious injury or death to another driver, the consequences listed above may be imposed.

“Implied consent” laws require drivers to submit to a breathalyzer test if they are pulled over by law enforcement, under suspicion of DUI. These laws essentially state that if you are driving, you are effectively consenting to DUI testing if required. This testing may include a breathalyzer test, and in some states, this also includes field sobriety tests. Although you may refuse testing, you could be violating implied consent laws.

How Can I Avoid A DUI Arrest?

Simply put, do not drive if you have been drinking alcohol. You should find an alternative means of transportation, such as a taxi or a bus. Additionally, you could still be held liable for prosecution for public drunkenness while walking to a cab or bus stop. An example of this would be how if you are going wine tasting, you should arrange for a guided wine tour and stop tasting at least an hour before the trip returns. Using a bicycle while intoxicated could result in a DUI/DWI arrest as well, and become part of your arrest record.

The penalties for refusing to submit to a DUI test can vary from a suspended license to a simple citation. Because of this, if you are trying to determine how many drinks before you are over the limit, keep in mind that at any moment when you are driving you can be required to take a breathalyzer test.

Do I Need An Attorney For Issues Associated With My State’s Legal Limit?

If you are being charged with a DUI, or have any questions regarding your state’s legal BAC limit, you will need to consult with an experienced and local DUI/DWI lawyer.

An attorney can answer your questions and help you determine your best course of legal action under the laws of your state. Additionally, an attorney will also be able to represent you in court, as needed.