Blood Alcohol Concentration (BAC) Calculator
Blood Alcohol Concentration, or BAC, measures the percentage of alcohol in your bloodstream. It’s key to making responsible drinking decisions.
You can use a BAC calculator to estimate the volume of alcohol per 100 ml of blood based on factors like weight, gender, and drink consumption. This information can guide you in assessing your impairment level and determine if you’re fit to drive.
Disclaimer: Online BAC calculators only provide estimates. Accuracy may vary depending on your metabolism and any alcohol interactions with other drugs.
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What is the Legal BAC Limit for Drivers?
In the U.S., the legal blood alcohol content limit for drivers is generally 0.08%. Going above this limit is illegal and considered a clear sign of impaired driving.
As BAC increases, motor skills, judgment, and decision-making abilities decline, posing risks to you and others. Legally, BAC impacts your responsibility behind the wheel—driving at or above 0.08% BAC can lead to severe legal consequences.
How to Use Stonewall’s BAC Calculator
Step 1. Select drink type and input alcohol content consumed in ounces.
Step 2. Type in your weight (lbs) and gender.
Step 3. Enter the total number of hours you were drinking.
Step 4. Calculate and match results with the table below.
While calculating blood alcohol levels can help you make safer choices, it’s only one part of the equation. If alcohol use has led to a DUI or feels harder to manage, you can explore our DUI classes and services for guidance.
What Happens To Your Body at Certain BAC Levels
Understanding how alcohol affects your body at different BAC levels is key to making safer choices. Here are the health effects that you may experience as your BAC rises.
| BAC (%) | Effects |
| 0.01 – 0.03 | Slight relaxation, slight impairment of coordination, mild mood enhancement. |
| 0.04 – 0.06 | Increased relaxation, minor impairment of motor control, potential for slurred speech, and slightly reduced judgment. |
| 0.07 – 0.09 | Significant impairment of coordination and judgment, blurred vision, and reduced reaction times. At 0.08, driving is legally unsafe in most states. |
| 0.10 – 0.12 | Clear impairment of motor skills, loss of balance, and major slurred speech. Driving is highly unsafe. |
| 0.13 – 0.15 | Severe impairment of judgment and motor control, nausea and vomiting may occur. |
| 0.16 and above | Intoxication increases. Risk of blackouts, loss of consciousness, and potential for serious health issues. |
Tip: Avoid driving at any BAC level that shows impairment.
Even a BAC of 0.01 can affect your coordination and judgment. Your risk of accidents rises significantly with each drink. If you feel impaired, use our blood alcohol calculator to gauge your level, but remember, the safest choice is to avoid driving altogether.
3 Tips to Stay Within Safe Blood Alcohol Concentration Limits
Don’t Drink and Drive
Plan for a safe ride using taxis or rideshares to avoid DUI risks.
While 0.08 is the legal limit in most states, lower BACs still affect reaction time and judgment.
Understand Your Limits
Your body processes alcohol differently based on personal factors like gender, weight, and health. Lighter individuals may feel alcohol’s effects faster than heavier individuals.
If unsure, consult a medical professional.
Know the Definition of “One Drink”
Knowing what constitutes “one drink” can help you manage your BAC.
Here’s a simple breakdown:
- 12 ounces of beer (about 5% alcohol) or about 350 ml
- 8 ounces of malt liquor (7% ABV) or about 240 ml
- 5 ounces of wine (about 12% alcohol) or about 150 ml
- 1.5 ounces of distilled spirits (about 40% alcohol) or about 40 ml
Frequently Asked Questions
Have more questions about blood alcohol content? Let us answer them.
How long does it take for alcohol to leave your system?
On average, your body processes about one standard drink per hour. However, this can vary based on weight, gender, and overall health.
What is a normal blood alcohol content level?
The normal BAC level is 0.00%. In the U.S., you’re considered legally impaired at 0.08%.
How to lower BAC quickly?
You can’t lower BAC quickly. Time is the only true way to decrease BAC. Cold showers or coffee might make you feel alert, but they don’t speed up alcohol metabolism.
Can food lower your BAC?
No. Eating before or while drinking may slow absorption, but once alcohol is in your bloodstream, food can’t reduce your BAC.
Does urinating lower BAC?
Not significantly. Your body eliminates most alcohol through the liver, not the bladder, so frequent bathroom trips won’t meaningfully reduce BAC.
Need Support? We’re Here to Help
If you face DUI charges or need guidance on alcohol-related issues, Stonewall Institute is here to help. Our Arizona DUI services offer expert help tailored to your needs.
We approach every case with professionalism and provide a safe, judgment-free space where you can find guidance, regain control, and take meaningful steps forward. Learn more about our DUI services today.
