Blood Alcohol Level (Free BAC Calculator)

How drunk will you get after three mimosas at brunch? 

Enter your weight, gender, and click on each the alcohol you’ve consumed to calculate your blood alcohol level.

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If you’re over 21, you might be able to answer that question with experience. A few mimosas may be a pleasant hair of the dog. Or it could be enough to keep you on the couch for the rest of the day. 

Can you drive after three mimosas at breakfast? 

That’s not an answer you should take a chance on. But, in the eyes of the law, the answer isn’t exactly clear. How strong were the mimosas? How big was each glass? When did you start drinking them, and how long has it been since you stopped? 

No one wants intoxicated drivers on the road. And for some people, three mimosas won’t get them intoxicated. But for others, it definitely will. It would be hard for the law to determine who is drunk and who isn’t just by the amount of drinks that they’ve had. There are many other factors that determine how intoxicated someone is. 

In DUI cases, law enforcement officers will rely on the measurement of a driver’s blood alcohol content, or BAC. If you are pulled over and suspected of drunk driving, you will likely have to take a chemical test that reveals your BAC. That small number, usually never higher than .2, may determine the course of your future. 

This article is all about BAC. I’m going to tell you how to figure out your BAC and what happens if you are pulled over and suspected of drunk driving. States handle these procedures differently, so it’s best to do a little research on your own to protect yourself in case you are pulled over. 

The safest thing to do is to not drink and drive. Period. Don’t do it. But as you’ll learn soon, perfectly legal activities may also increase your BAC and put you at risk of a DUI. To prevent fighting for your freedom in court, educate yourself and keep a BAC calculator nearby.

BAC Chart 

blood alcohol content table

What Is Blood Alcohol Level? 

Your BAC is the measurement of how much alcohol has made it to the bloodstream. If your blood contains 1000 parts blood and one part alcohol, your BAC is .10. It’s likely that you’ll blackout from drinking at .20. If your BAC reaches .25, you will get alcohol poisoning. 

In order to understand BAC, it’s important to know how alcohol travels through the body. When you take a swig of booze, it travels down to the stomach. About 20% of alcohol is absorbed here. Most of it goes to the small intestine. The alcohol in the small intestine then makes contact with blood vessels and moves through the bloodstream. 

On most nights out, you shouldn’t be reaching .20. But it’s often hard to tell whether you’re at .07 or .08, the legal limit for driving while intoxicated. So let’s talk about the factors that may put you over that line (and behind bars.) 

What Influences Blood Alcohol Level? 

The amount of alcohol you drink will obviously influence BAC. But there are other factors that influence how much alcohol is in your blood: 

  • Body type 
  • Ethnicity or family history 
  • Biological Sex 
  • How much food is in your stomach
  • Hydration levels 
  • How quickly you’ve consumed each drink
  • Any medications or controlled substances in your blood
  • How long it’s been since you had a drink 
  • Strength of each drink you’ve consumed 

If you’ve had experience drinking, you probably know all of this already. You might see friends with different body types who are able to drink more or less than you. If you start drinking in the morning without any breakfast, you might feel it “hit” harder than if you’ve had a full meal and then start drinking. 

Not all of these factors can be quantified, so know that online BAC calculators are not guaranteed to provide an accurate answer. This is why so many BAC test apps are removed from app stores!

How Long Does It Take For Alcohol To Leave Your System?

You might also know that it takes the liver one hour to process a standard drink. If you drink a beer and wait an hour, you should be good to go. But you can’t just take four shots, wait four hours, and expect to be a-okay. 

If you take on more alcohol than your liver can handle, that’s when your BAC really starts to rise. Alcohol will remain in the tissues and bloodstream until the liver can break it down. This means that it could take much longer than four hours to sober you up.

It’s easier said than done, but it’s recommended that you wait an hour or have a non-alcoholic beverage in between standard drinks. (And by non-alcoholic, I don’t mean Red Bull. Water is best.)

A Note About An Empty Stomach and BAC 

It’s also important to note that the food in your stomach previous to drinking influences BAC. Eating a bunch of junk food after some shots isn’t going to magically make you sober and ready to drive. The only thing that will decrease your BAC is time. The body needs to process the alcohol in your blood in order to decrease BAC. It can only process a drink an hour, but it usually needs more time. 

Laws on Blood Alcohol Level and Driving 

Blood alcohol level is usually brought up in stories about DUI, DWI, or OUI. That’s right. Not all states have a charge called “DUI.” Each state handles how DUIs are charged, the penalties for this crime, and even what the crime is called. In Texas, there is no such thing as a DUI charge. They do, however, have a “Driving While Intoxicated” charge, abbreviated to DWI. This charge covers other controlled substances that might be in your system while you’re behind the wheel.

There is one thing that all states have in common: the per-se BAC limit across the country is .08. If someone has a blood alcohol level of .08 or higher, they are considered legally drunk and will likely be charged for driving while under the influence of drugs or alcohol. 

The penalties for DUI will vary by state. 

In Arkansas, a first-time DWI conviction results in the following penalties:

  • Fines of up to $1,000
  • Up to a year in prison (or 30 days community service) 
  • Loss of driver’s license for up to six months
  • Required alcohol education 

California’s penalties are a little bit different: 

  • Fines of up to $1,000 
  • 2-180 days behind bars (or up to five years of probation) 
  • Required education (up to nine months of classes, costing up to $1,200) 
  • Loss of driver’s license for six months
  • Restricted license with ignition interlock device (IID) 

An IID is a device that requires you to take a blood alcohol level test before turning on your car. This ensures that you are not drinking and driving after you are out of jail. California is currently testing out a pilot program that puts more IIDs in offenders’ cars. If you are in Arkansas, you may qualify to get an IID installed in your car. With an IID, your driving will still be restricted to places like school, work, or a treatment facility. 

IIDs are generally expensive, costing hundreds of dollars to install and keep in your car. Many states will suspend an offender’s license until they can get the IID installed. 

Other BAC Measurements

Aggravating Factors

All of these penalties are just for a first-time conviction without any injuries or aggravating factor. “Aggravating factors” are factors that make a crime more serious. For example, if you were driving drunk with children in the car, you may face extra charges or penalties. If your BAC was exceptionally high, you may also face additional penalties. 

States have different laws for what “counts” as an aggravating factor and what BAC qualifies for enhanced penalties. In Georgia, a BAC of .15 will come with extra penalties. In Idaho, this number is increased to .20. In Hawaii, there is no BAC level for enhanced penalties. 

Zero-Tolerance BAC Level 

States also have different “zero-tolerance” BAC laws for underage drivers. Federal law prohibits the purchase of any alcoholic beverage until you’re 21. While states uphold this law on purchasing, rules for consumption may vary. In Texas, a minor can drink only if they are in the presence of their parent or legal guardian. (And this doesn’t mean a friend over the age of 21.) 

But what happens if that Texan gets behind the wheel? They might get charged with DWI. If a minor’s BAC is above .00 while they are driving, they are breaking the law. Even if they had a glass of wine with a parent at dinner and “feel fine.” 

A handful of states have a zero-tolerance BAC level of .02. California’s zero-tolerance BAC level is .01. Check your state laws to understand the rules of driving while intoxicated, and the penalties you could face if convicted. 

Can Blood Alcohol Tests and Breathalyzers Be Wrong?

Have I scared you out of drinking and driving yet? Good. Every day, at least 30 Americans die in a DUI-related crash. These statistics are astounding. You can save lives by ordering a rideshare or choosing a designated driver. 

Not all drunk drivers are caught, causing many of the accidents that happen throughout the country. But there is another side to this coin. Not all people pulled over for drunk driving, or arrested for drunk driving, are actually breaking the law. 

There are other factors that could influence the BAC that shows up in a Breathalyzer or chemical test:

  • Presence of legal medications 
  • Presence of legal substances with alcohol in the breath (including mouthwash) 
  • Inability to produce enough breath to get a reading
  • Failure to reset or recalibrate device after a previous reading
  • Lack of training 
  • Human error using a Breathalyzer or analyzing results 

How rare is it that you’ll get a false reading on a Breathalyzer? Not as rare as you might think. In 2019, Massachusetts and New Jersey threw out over 30,000 Breathalyzer results. That’s not common for other types of forensic evidence. It’s one of the largest exclusions of forensic evidence in American history. 

These tests can present a number that is over 40% higher than your actual results. (They can also show results that are significantly lower than your actual BAC, but don’t rely on that chance.) 

man taking a breathalyzer in front of a meal

The best thing that you can do to prevent an arrest based on false results is to educate yourself on your rights and don’t drink and drive. You can’t be arrested for taking an Uber while intoxicated. 

How long can you detect alcohol in your system?

What you use to measure the alcohol level in your body makes a difference here. In most cases, alcohol can be detected for up to 24 hours after you started drinking. Here is a more detailed answer to the amount of time it takes for alcohol to leave your body:

  • Breath test: can detect alcohol for up to 24 hours after your last drink.
  • Urine test: can generally detect alcohol between 12 – 48 hours after your last drink, with some advanced tests (EtG) that may be able to detect alcohol up to 80 hours, or 3-5 days, after your last drink.
  • Hair test: can detect alcohol for up to an incredible 90 days, although these kinds of tests are rare.
  • Blood test: can detect alcohol for up to 12 hours after your last drink.
  • Saliva test: can only detect alcohol for 2 hours after your last drink.
  • Sweat: can probably detect alcohol for up to 2 hours after your last drink.

What happens at each Blood Alcohol Concentration level?

Everyone is different and will experience the effects of alcohol differently, but we’ve put together this general guide to what you might expect at each BAC level:

  • Between 0.01 – 0.03% BAC, you might start to feel relaxed and possibly even find yourself in a good mood.
  • Between 0.04 – 0.07% BAC, you might start to feel increasingly warm. You can also expect to start having problems with your balance, vision and speech.
  • At 0.08% BAC, in most states, you’re now illegal to drive a vehicle. This is because the alcohol in your system is now seriously affecting your reflex times so, there’s a time lag between thinking about doing something and your body responding. You can also expect to see problems with coordination, moving around safely (you might fall over), and speaking and hearing clearly. Judgement compromised and your short-term memory can start to be affected.
  • Between 0.09 – 0.12% If you were on the edge at 0.08%, at this BAC level, you’ll definitely be seeing problems with delayed reactions, struggling with your coordination (like being unable to walk in a straight line), and will likely be slurring a lot when you talk.
  • Between 0.13 – 0.15% BAC, we’re now looking at serious lack of motor control. This means you’re going to be super clumsy and unable to navigate simple obstacles, which won’t be helped by increasingly blurred vision. You might also start to experience mood side effects such as anxiety or paranoia.
  • Between 0.16 – 0.20% BAC, those mood changes will get worse and you’re likely to also start to feel nauseated. 
  • Between 0.25 – 0.30% BAC, we’re talking serious intoxication. You could be experiencing alcohol poisoning. At this BAC level, you’re probably not going to be able to walk unaided, and your ability to think straight will have completely disappeared. You might experience vomiting or even have a blackout.
  • Between 0.35 – 0.39% BAC, isn’t a place you want to be. At this BAC level, you’re on the brink of a coma, and you are likely to lose consciousness.

Once you hit 0.40%, you’re in real trouble. You could fall into a coma and there is now a serious risk of death because you could stop breathing (respiratory failure).

How long does it take to get alcohol out of your system? 

The short answer is: it depends.

I know! Not helpful, right? There’s a reason for the fluffy answer though. Turns out that there’s a bunch of factors that determine how long alcohol takes to get out of your system, which include:

  • What you’re using to measure the blood alcohol concentration level in the body (blood, urine, breath, or hair).
  • If you drank beer, wine or liquor, as each of these break down differently in the body.
  • Personal factors such as weight, sex and age

How you metabolize alcohol

Without getting overly technical, basically, your body processes alcohol from your gastrointestinal tract (your throat all the way to your stomach and intestines). Around 20% gets absorbed directly into your bloodstream, which carries it around the body and into the brain. The other 80% goes to your small intestine and then into your bloodstream when your body then tries to get rid of it. This work is mostly done by your liver, with less than 10% of it being eliminated through your lungs, kidneys and sweat.

Alcohol metabolism

If we just ignore all these extra factors and just focus on the science stuff, we know that for the average person, the body metabolizes alcohol at a rate of 20mg/dL per hour. It’s important to make the point that this isn’t related to your blood alcohol concentration (BAC) level. While it takes pretty much everyone the same amount of time to process alcohol through their system, people can have completely different BAC levels!

What about the different type of alcohol?

These are just general estimates, as another factor that play a part is the amount or proof of alcohol in each drink:

  • A small shot of liquor generally takes up to 1 hour to metabolize.
  • A pint of beer generally takes up to 2 hours to metabolize.
  • A large glass of wine generally takes up to 3 hours to metabolize.

It goes without saying that the more drinks you have, the longer it will take for your body to process and eliminate the alcohol from your system (and the more side effects you’ll experience).

Your Rights When Pulled Over 

man taking a breathalyzer in his car

Implied Consent and Refusing a Chemical Test 

If you’re pulled over by the police and they ask you to take a Breathalyzer, you can just say no, right? 

Wrong…maybe. 

Each state handles this process differently. If you have a driver’s license in a state with implied consent, you can’t just say no to a chemical test if you’ve been suspected for drunk driving. Well, you can, but you will have to face some penalties. In Massachusetts, for example, refusing a chemical test may result in losing your license for six months. Prosecutors will not be able to use your refusal as “evidence” that you drove while intoxicated. Other types of evidence, including witness testimony, may convict you. 

In most of these cases, a police officer will need a reason to pull you over. Maybe you were swerving. Or speeding. Maybe you didn’t have your headlights on, and when rolling down your window, the officer saw an empty beer can. Whatever the reason is, it will have to raise suspicion that you were driving under the influence. Officers may be instructed to conduct field sobriety tests (walking in a straight line, etc.) before a chemical test can be administered. 

Check with state laws to see whether you can refuse a chemical test without penalty, and the requirements for pulling you over in the first place. 

DUI Checkpoints

It’s also useful to look at whether your state allows DUI checkpoints. These checkpoints are areas on the side of the road where every car gets stopped and every driver must take a Breathalyzer to keep driving. If this sounds absurd, your state may not have them. 

There are ten states that claim that DUI checkpoints are unconstitutional:

  • Idaho
  • Iowa
  • Michigan
  • Minnesota
  • Oregon
  • Rhode Island
  • Texas
  • Washington
  • Wisconsin
  • Wyoming 

Every other state adheres to federal law, which says that this type of stop is permissible. Again, it’s possible to refuse a chemical test at these checkpoints, but you might face penalties. Refusing a chemical test at an unlawful checkpoint may result in your case getting thrown out. To keep yourself safe, assume that all DUI checkpoints are lawful and follow the officer’s orders at the checkpoint. You can always fight a checkpoint or your test results in court. 

Stay Safe and Understand Your BAC 

To keep yourself safe, you should also assume that if you plan on drinking, you should plan on calling a rideshare or having a designated driver. But I know that this doesn’t always work out the way we planned. So keep this BAC calculator handy if you’re in a pinch.

Theodore T.

Theodore is a professional psychology educator with over 10 years of experience creating educational content on the internet. PracticalPsychology started as a helpful collection of psychological articles to help other students, which has expanded to a Youtube channel with over 2,000,000 subscribers and an online website with 500+ posts.