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
Note: Effects may vary by individual. Any amount of alcohol can impair judgment.
Safety Guidelines and Legal Information
- • Eat before and while drinking
- • Pace your drinks
- • Stay hydrated with water
- • Know your limits
- • Plan safe transportation
- • 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
- • 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 = (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
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 × 1000 × 0.68) - (0.015 × 2)
- 3. BAC = 0.064%
This BAC of 0.064% indicates mild impairment.
Standard Drink Equivalents
- • 12 oz (355 ml)
- • 5% alcohol
- • 1 standard drink
- • 5 oz (148 ml)
- • 12% alcohol
- • 1 standard drink
- • 1.5 oz (44 ml)
- • 40% alcohol
- • 1 standard drink
Important Safety Information
Your body processes alcohol at about one standard drink per hour
Legal limit is 0.08% in most places, but impairment starts much lower
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.
Get accurate BAC results instantly based on your inputs.
Estimate when you'll be safe to drive based on your current BAC.
Receive tailored advice based on your BAC level and situation.
Understand the legal BAC limits and their implications.
See how different types of alcohol affect your BAC.
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
Input your weight, gender, number of drinks, and drinking duration into our calculator.
Receive instant results with your estimated BAC level and impairment status.
Get personalized safety advice and estimated sobering time based on your BAC level.
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