How Many Drinks Does It Take To Reach the .08 BAC Limit?

You’re at a new restaurant, and the waiter suggests the latest cocktail on the menu that pairs well with your meal. Sounds intriguing, but you also need to drive home. You’re left wondering, “How many drinks can I have to make sure I stay under the .08% legal driving limit?”.

It’s a valid question many of us ask ourselves. However, the answer isn’t as simple as one or two drinks. There are many factors that influence our blood alcohol concentration. Since driving under the influence has serious implications, let’s take a deep dive into how we can stay below the legal limit and prioritize our health and safety. 

Understanding Legal Blood Alcohol Concentration (BAC) Limits

Blood alcohol concentration (BAC), also known as blood alcohol content, is the amount of alcohol per 100 mL of our blood. It’s used to measure our level of intoxication for legal or medical purposes. Our BAC represents different levels of intoxication, which are associated with different effects. 

Since drinking affects our cognitive and motor function, a legal driving limit was created to prevent accidents from an impaired ability to operate a vehicle. In the U.S., the legal driving limit is .08 BAC. At a BAC level of .05% to .07%, the effects of alcohol start to be noticeable with effects feeling warm, lightheaded, relaxed, or uninhibited. At a BAC of .08% to .10%, our vision, reflexes, and coordination are compromised. In other countries, the legal driving limit ranges from zero to .08 BAC. 

Driving under the influence (DUI) can result in fines, jail time, revocation or suspension of licenses, increased insurance fees, and civil lawsuits. Specific groups such as commercial drivers or underage drinkers fall under the zero-tolerance policy and can face greater consequences if exceeding the legal driving limit. If we’re choosing to drink, how can we ensure that we stay under the .08 BAC limit?

Estimating Drinks to Reach .08 Alcohol Level

The main factors that affect our BAC are our weight and gender. BAC is calculated using the Widmark formula, which is:

[Alcohol consumed in grams / (Body weight in grams x r)] x 100 = BAC “R” in the formula is the gender constant which is .55 for females and .68 for males.

Another way to estimate BAC is shown in the following State of West Virginia BAC Chart. 

We can estimate our BAC by tracking the number of standard drinks we consume and the time since our first drink. Note that a “standard drink” varies by different types of alcohol. For example, the number of beers vs. the number of glasses of wine we can drink to reach .08 BAC will vary. Use a standard drink calculator for a more accurate measure of how much we’re actually consuming.

After determining the number of standard drinks and referencing the chart, we can estimate our BAC by subtracting the percentage of alcohol “burned” based on how much time has passed. That is .015% per hour. According to the chart, .08 BAC is anywhere between 2 to 4 standard drinks for women and 2 to 5 standard drinks for men. 



Forbes Advisor makes it easy to figure the percentage you can subtract:

• 1 hour from last drink: 0.015%
• 2 hours from last drink: 0.030%
• 3 hours from last drink: 0.045%
• 4 hours from last drink: 0.060%
• 5 hours from last drink: 0.075%
• 6 hours from last drink: 0.090%

Remember, even if we don’t feel intoxicated, our BAC may still be above the legal limit for driving.

We can also use online BAC Calculators to help us do the math. However, it's important to remember there are many factors that influence our BAC, and these tools only help us estimate it. Let’s explore additional considerations to ensure we don’t exceed the .08 BAC limit. 

Factors That Influence BAC

Although BAC calculators give us a general idea of how alcohol will impact us, individual factors greatly affect this estimate. Taking note of these additional influences helps us get a better understanding of our own limits.

• Body composition. We know that weight is a major factor in calculating BAC, but our body composition impacts our weight and how we metabolize alcohol. Our body composition, including how much fat and muscle we have, influences the fluid volume in our body since muscle contains more water than fat. This means that two people with the same weight who drink exactly the same amount of alcohol can have different BAC levels. 
• Alcohol metabolism. This refers to how our body breaks down and eliminates alcohol. The faster we metabolize alcohol, the faster our BAC drops. Factors such as our liver health, rate of alcohol absorption, and the presence of other substances can impact alcohol metabolism — creating major variations from person to person. 
• Consumption factors. Not only the amount of alcohol we drink but also how quickly we drink it can impact our BAC. This is because our liver, which metabolizes a majority of alcohol, can only do so at a certain rate. When we drink too quickly, our liver gets overloaded, and our metabolism slows down. Whether we drink on an empty stomach or soon after a meal is another consideration. Without food, alcohol is absorbed in our stomach faster, which also impacts how quickly it is eliminated.

As we can see, many factors come into play when determining our BAC. Even if we’ve followed the BAC chart or used an online calculator, our BAC may still exceed the .08% limit. What are the consequences?

Implications of Exceeding .08 BAC

The legal driving limit is .08 BAC, but there are many implications of exceeding this limit aside from legal consequences. Let’s take a more in-depth look at them.

• DUI penalties. Direct DUI consequences can include fines, suspension of our driving license, jail time, and increased insurance rates. Certain situations, such as harm to property or another person, can warrant greater consequences.
• Indirect DUI consequences. DUIs can affect us not only legally but also personally and professionally. Personal consequences may include financial strain from fines, lack of family presence from jail time, and stress from legal or social impacts. Also, DUIs stay on our record for a period of time, which may impact employment opportunities or affect our current professional reputation. 
• Increased risk of alcohol-related accidents. Any amount of alcohol impairs our cognitive and motor function, but the effects of alcohol become more noticeable when our BAC is over .05%. At this level, our risks of alcohol-related accidents, such as falling, drowning, or falling victim to a crime, increase significantly. 
• Negative health effects. The toxins in alcohol are detrimental to our physical and mental health. Excessive consumption of alcohol is associated with health conditions, such as liver disease, cardiovascular disease, certain types of cancer, diabetes, anxiety, and depression.

With a clearer understanding of the risks associated with a BAC above .08%, let’s explore strategies to ensure our BAC remains below this threshold.

Staying Below .08 BAC

Ensuring our BAC is below .08% doesn’t eliminate the risks of alcohol, but it does minimize them. We can practice staying below the legal limit by implementing these mindful drinking strategies.

• Learn more. The more we learn about alcohol and its effects on our body, the more informed choices we can make when drinking. 
• Set limits. Now that we have a better understanding of how many standard drinks can raise our BAC to .08% and above, we can set limits when we drink to help us stay below the legal threshold. 
• Quit or cut back. Quitting or cutting back on alcohol reduces the risk of DUIs and minimizes alcohol-related harm. 
• Don’t estimate. To be sure we aren’t driving under the influence, it’s best not to estimate. We can easily check our BAC by using a breathalyzer. If it’s at or above .08%, wait or let someone else drive. 
• Get support. If you have trouble staying under the .08% limit or are concerned about your relationship with alcohol, reach out for support. Identify an accountability buddy to make sure you stick to the limits you set for yourself or explore professional treatment options to develop positive skills. 

While the number of drinks it takes to reach .08 BAC may differ from person to person, we can all benefit from quitting or cutting back on alcohol.

Scaling Back

Getting to the bottom of how many drinks it takes to reach the .08 BAC limit is like piecing together a complex puzzle. As we strive toward more mindful drinking, it's important to remember that less means more — more clarity, control, and authenticity. Staying below the legal .08 BAC limit not only helps us avoid a DUI but also opens the door to a healthier, happier life. So, the next time you drink, stay below .08%, or make sure to wait!