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BAC Calculator

Calculate your estimated Blood Alcohol Concentration (BAC) based on drinks consumed, body weight, gender, and time elapsed. Understand impairment levels and time to sobriety.

Estimated BAC

Blood Alcohol

0.038%

Mild

Legal but impaired (under 0.08)

Hours to Sober~2.5 hrs
Drinks Processed1.0 of 2

This is an estimate only. Actual BAC varies. Never drink and drive.

Estimated BAC

Blood Alcohol

0.038%

Mild

Legal but impaired (under 0.08)

Hours to Sober~2.5 hrs
Drinks Processed1.0 of 2

This is an estimate only. Actual BAC varies. Never drink and drive.

Drinks Consumed

2 drinks
1 drinks15 drinks
1 hrs
0 hrs12 hrs

Your Information

lbs

Women typically have higher BAC due to body composition differences.

Effects at Your BAC Level

Mild(0.038% BAC)
  • •Lowered inhibitions
  • •Mild euphoria
  • •Slight impairment of judgment
  • •Decreased alertness

BAC Impairment Levels

0.00%Sober
0.02-0.05%Mild Impairment
0.05-0.08%Impaired
0.08%+Legally Drunk (US)
0.15%+Severe Impairment
0.30%+Life Threatening

What is a Standard Drink?

One standard drink contains approximately 0.6 oz (14g) of pure alcohol:

Beer

12 oz

5% ABV

Wine

5 oz

12% ABV

Liquor

1.5 oz

40% ABV

Malt Liquor

8 oz

7% ABV

Important Safety Information

  • • This calculator provides estimates only. Actual BAC varies significantly between individuals.
  • • Never drive after drinking. Use a designated driver, taxi, or rideshare.
  • • Alcohol affects judgment before you feel drunk. Don't rely on how you feel.
  • • If someone shows signs of alcohol poisoning (confusion, vomiting, seizures, slow breathing), call 911 immediately.

Explore Drinking Scenarios

Explore how changes affect your results

BAC Reference Comparison

Compared to the general population

Your BAC

3.8 % × 100

Percentile

40th

Below average - looking good!

Distribution

You

Sober

0.0

Social

2.0

Impaired

5.0

Legal Limit

8.0

Dangerous

15.0

Your Ranking

Top 40%

60% are higher

Safety Information

Based on your BAC results

0/4 completed
⚕️ MedicalOptional

Current Status

At 0.038% BAC, you have some alcohol in your system. Effects are minimal but present.

🌙 LifestyleRecommended

Time to Sober

Your body processes alcohol at about 0.015% per hour. You'll need approximately 2.5 hours to be fully sober.

🥗 NutritionOptional

Stay Hydrated

Drink water between alcoholic drinks. This doesn't reduce BAC but helps prevent dehydration and may reduce hangover symptoms.

Frequently Asked Questions

What is Blood Alcohol Concentration (BAC)?

BAC measures the percentage of alcohol in your bloodstream. A BAC of 0.08% means 0.08 grams of alcohol per 100 milliliters of blood. This is the legal limit for driving in most US states.

How accurate is this BAC calculator?

This calculator uses the Widmark formula, which provides estimates based on average alcohol metabolism. Actual BAC varies based on food intake, medications, liver health, and individual metabolism. This is for educational purposes only.

How long does it take alcohol to leave your system?

The body metabolizes alcohol at about 0.015% BAC per hour (roughly one standard drink). A person with 0.08% BAC would take about 5-6 hours to become sober. Sleep, coffee, and cold showers do NOT speed up this process.

What factors affect BAC?

Key factors include: body weight (higher weight = lower BAC), gender (women typically have higher BAC per drink), food intake (food slows absorption), drinking speed, and individual metabolism.

Is it safe to drive if I'm under 0.08%?

Even below 0.08%, alcohol impairs judgment, reaction time, and coordination. Some states have lower limits (0.05%), and commercial drivers often have 0.04% limits. When in doubt, don't drive.

Formula:
By Joseph OrdunaHow this works

How this works

Uses the Widmark formula: BAC = (alcohol grams × 100) / (body weight in grams × distribution ratio) − hourly elimination rate × hours since first drink. Distribution ratio defaults to 0.68 (male) and 0.55 (female). Elimination averages 0.015% per hour.

What this tool can’t do

  • Widmark is an average-body estimate; individual variation in enzyme levels, food intake, and hydration produces substantial differences.
  • Never rely on a BAC calculator to decide whether it is safe to drive. If you have been drinking, do not drive.

When to consult a professional

Never use this tool as a legal or safety arbiter of whether you can drive, operate machinery, or perform any other BAC-regulated activity. The only safe BAC for driving is zero.

Sources

  1. [1]
    Centers for Disease Control and Prevention (CDC)
    Official sourcecdc.govAccessed Apr 21, 2026
  2. [2]
    National Institutes of Health (NIH)
    Official sourcenih.govAccessed Apr 21, 2026
Joseph Orduna
Founder & Software Engineer

Full-stack software engineer specializing in embedded systems, web architecture, and AI/ML. Founder of Practical Web Tools. Built the gesture-controlled drone IP acquired by KD Interactive (Aura Drone, sold on Amazon).