How Many Drinks Does it Take to Get a DUI?
While drinking alcohol during dinner at a restaurant, at a bar or nightclub, or at a party, a person may try to count the number of drinks they have had so they can decide whether it is safe to drive home. While one or two drinks over a few hours may not cause serious intoxication, more drinks could put a person over the legal limit, which could lead to charges of driving under the influence (DUI).
In fact, there is no simple guideline that applies to everyone. Two people who drink the same amount of alcohol over the same period of time can end up with very different levels of intoxication. Understanding how alcohol affects the body and how DUI laws work can help a person understand whether they could face DUI charges if they drive after drinking.
How Many Drinks Will Put You Over the Legal Limit?
For many people, two to four standard drinks within an hour or two will put them over the legal limit. In nearly every state, the legal limit for drivers who are over the legal drinking age of 21 is a blood alcohol concentration (BAC) of .08%. BAC measures how much alcohol is in a person’s bloodstream. A smaller person may reach the legal limit after a few drinks, while a larger person may be able to drink several drinks over the same period before reaching that level.
What Counts as a Standard Drink?
The level of intoxication a person may experience will depend on the amount of alcohol in a drink. When people discuss drinks, they may refer to a standard drink, which contains about 14 grams, or roughly 0.6 ounces, of pure alcohol. According to the National Institute on Alcohol Abuse and Alcoholism, each of the following is considered one standard drink:
- 12 ounces of regular beer with about 5% alcohol
- Five ounces of wine with about 12% alcohol
- 1.5 ounces of liquor, such as vodka, whiskey, or rum, with about 40% alcohol
Many drinks served at bars and restaurants contain more than one standard drink. A pint of craft beer, a large glass of wine, or a mixed drink with multiple shots of liquor may be the same as two or more standard drinks. This is one reason why counting the number of drinks a person has had is not always a reliable way to determine intoxication.
How Many Drinks Can Lead to Intoxication Based on Weight and Gender?
The human body generally removes alcohol from a person’s system at a rate of about .015 percent BAC per hour. This amount is less than the amount of alcohol in one standard drink. Drinking faster than the body can process alcohol will cause BAC to rise.
Estimates based on the Widmark formula, a calculation that scientists and courts commonly use to estimate BAC, can be used to determine how many drinks within a certain time period can cause a person to be over the legal limit. The approximate number of drinks that may bring a person to a BAC of about .08% include:
- A 120-pound woman who has two drinks in one hour
- A 140-pound woman who has three drinks in two hours
- A 180-pound woman who has four drinks in two hours
- A 140-pound man who has three drinks in one hour
- A 160-pound man who has four drinks in two hours
- A 200-pound man who has five drinks in two hours
These numbers are only estimates. A person’s actual BAC could be higher or lower depending on a variety of factors. The only way to know a BAC for certain is through a test that measures the level of alcohol in a person’s breath, blood, or urine.
Why Do Women Often Reach the Legal Limit Faster?
Women generally have less water in their bodies than men who are around the same weight. Because alcohol spreads through the water in the body, the same amount of alcohol can become more concentrated in a woman's bloodstream. Women also tend to have lower levels of an enzyme that breaks down alcohol in the stomach.
What Other Factors Affect a Person's Level of Intoxication?
Body weight and gender are only part of the picture that can affect BAC levels. Other factors can raise or lower a person’s BAC, including:
Food
Eating before or while drinking can slow down how quickly alcohol enters the bloodstream. Drinking on an empty stomach can cause a person’s BAC to rise faster.
Speed of Drinking
Taking shots or finishing several drinks during a short period can increase a person’s BAC. If drinks are spread out over a few hours, the body will have more time to process the alcohol.
Medications
Some prescription and over-the-counter medications, such as allergy pills, sleep aids, and anxiety medications, can increase the effects of alcohol. Even if a person’s BAC is low, the combination of alcohol with a medication could lead to intoxication.
Other Personal Factors
Issues such as age, overall health, fatigue, body fat percentage, and alcohol tolerance can all affect how many drinks it takes to become intoxicated. A person with a high tolerance because they drink alcohol regularly may not feel drunk, but their BAC can still be over the legal limit.
Can You Be Charged With DUI if You Are Below the Legal Limit?
If a person’s BAC is .08% or higher, they can be charged with DUI based on that number alone. This is known as a "per se" DUI, which means that a BAC measurement is enough to charge a person with DUI, regardless of whether they actually felt intoxicated. However, a person may also face DUI charges with a BAC below .08%, depending on state laws and the circumstances of a case.
In most states, a person can be charged with DUI or another related offense if alcohol affected their ability to drive safely, regardless of their actual BAC. An officer may decide to arrest a person based on their observations of signs of intoxication, such as slurred speech or failed field sobriety tests.
Legal Help From a DUI Defense Attorney
A DUI charge can lead to license suspension, fines, higher insurance rates, and possible jail time, even for a first offense. Because BAC estimates and testing are not perfect, there may be questions about whether a breath or blood test was accurate or whether a police officer followed the proper procedures during a traffic stop. A DUI defense lawyer can review the evidence against a person, challenge test results or field sobriety tests when appropriate, and explain how state laws apply to a specific case. They can provide guidance on the best steps to take to resolve a DUI case successfully.
