Free Online BAC Calculator

BAC Calculate

Stay Safe & Informed

Calculate your Blood Alcohol Content (BAC) instantly and get personalized safety recommendations. Make informed decisions about your alcohol consumption.

Key features of our BAC calculator:

Real-time BAC estimation
Safety recommendations
Sobriety time estimates

BAC Effects Chart

Understanding Blood Alcohol Content Levels and Their Effects

BAC Levels and Effects

0.02 - 0.03%Mild mood changes

0.04 - 0.06%Relaxation, mild euphoria

0.07 - 0.09%Impaired judgment and coordination

0.10 - 0.12%Significant impairment

≥ 0.15%Dangerous intoxication

Note: Effects may vary by individual. Any amount of alcohol can impair judgment.

Safety Guidelines and Legal Information

Prevention Tips:

•Eat before and while drinking
•Pace your drinks
•Stay hydrated with water
•Know your limits
•Plan safe transportation

Legal Information:

•Legal limit is 0.08% in most states
•Zero tolerance for under 21
•Commercial drivers limit: 0.04%
•DUI penalties are severe
•Implied consent laws apply

Safety Measures:

•Use ride-sharing services
•Have a designated driver
•Never drink and drive
•Keep emergency contacts handy
•Monitor friends' consumption

If you or someone you know needs immediate assistance, call emergency services

How to Calculate BAC

Understanding the factors that affect your Blood Alcohol Content

BAC Formula

BAC = (Alcohol in grams × 100) ÷ (Weight in grams × Gender Constant) - (0.015 × Hours)

Key Factors:

Weight: Heavier people have lower BAC
Gender: Women generally have higher BAC
Alcohol consumed: Standard drinks (14g alcohol each)
Time: Alcohol metabolizes at ~0.015% per hour

Example BAC Calculation

For someone who is:

Weight: 70 kg (male)
Drinks: 3 standard drinks
Time: 2 hours since first drink

1. Alcohol = 3 × 14g = 42g

2. BAC = (42 × 100) ÷ (70 × 0.68) - (0.015 × 2)

3. BAC = 0.064%

This BAC of 0.064% indicates mild impairment.

Standard Drink Equivalents

Beer

• 12 oz (355 ml)
• 5% alcohol
• 1 standard drink

Wine

• 5 oz (148 ml)
• 12% alcohol
• 1 standard drink

Spirits

• 1.5 oz (44 ml)
• 40% alcohol
• 1 standard drink

Important Safety Information

Time Matters

Your body processes alcohol at about one standard drink per hour

Know Your Limits

Legal limit is 0.08% in most places, but impairment starts much lower

Plan Ahead

Always arrange for a designated driver or alternative transportation

Everything you need to stay safe

Our comprehensive BAC calculator provides accurate results and safety recommendations to help you make informed decisions.

Real-time BAC Estimation: Get accurate BAC results instantly based on your inputs.
Sobriety Time Prediction: Estimate when you'll be safe to drive based on your current BAC.
Personalized Safety Tips: Receive tailored advice based on your BAC level and situation.
Legal Limit Awareness: Understand the legal BAC limits and their implications.
Drink Type Analysis: See how different types of alcohol affect your BAC.
Privacy & Security: Your data is never stored or shared with third parties.

How the BAC Calculator Works

Understand your alcohol consumption and make safe decisions in just a few steps

Enter Your Details: Input your weight, gender, number of drinks, and drinking duration into our calculator.
Get Your BAC Estimate: Receive instant results with your estimated BAC level and impairment status.
Safety Recommendations: Get personalized safety advice and estimated sobering time based on your BAC level.
Plan Your Next Steps: Understand when it will be safe to drive and get alternative transportation options.

Trusted by Thousands of Users

See what our users say about their experience with our BAC Calculator

David Thompson

Safety Advocate

This BAC calculator helps me make informed decisions about drinking responsibly. The safety tips are especially valuable!

Lisa Chen

Event Planner

I recommend this tool to my event clients. It's a great way to promote responsible drinking at social gatherings.

Mark Wilson

Health Educator

As a health educator, I appreciate how this tool helps people understand BAC levels and promotes safe drinking habits.

Frequently Asked Questions

Find answers to common questions about BAC calculation and alcohol safety