BAC Calculator - Calculator Converter Pro

Blood Alcohol Content (BAC) Calculator

Estimate your blood alcohol concentration based on drinks consumed and personal factors

Gender
Weight
kg
Measurement System
Hours Since First Drink
hours
Drinks Consumed
Beer
355 ml (12 oz)
5% alcohol
Wine
148 ml (5 oz)
12% alcohol
%
Additional Factors (Optional)
Your Blood Alcohol Content Results
Estimated based on your drinking pattern and personal factors
0.05
Social Impairment
Mild impairment - judgment and coordination affected
0.00
0.02
0.05
0.08
0.10
0.12
0.15
0.20
BAC Impairment Scale
Sober
0.00 - 0.03%
Social
0.03 - 0.06%
Impaired
0.06 - 0.10%
Drunk
0.10 - 0.15%
Danger
0.15%+
Time Estimation to Sober Up
Hours to reach legal limit
Below 0.08% BAC
5.0
Hours to be completely sober
Below 0.02% BAC
1.0
Hours to peak BAC
Maximum concentration
Legal Limits by Country
United States
0.08%
Standard DUI limit for drivers 21+
Most of Europe
0.05%
Standard limit for experienced drivers
Zero Tolerance
0.00% - 0.02%
Commercial drivers, under 21, some countries
BAC Effects and Symptoms
BAC Range Category Typical Effects Physical Symptoms Driving Ability
0.00 - 0.03% Sober No obvious effects Normal behavior Normal
0.06 - 0.10% Impaired Reduced inhibition, impaired judgment Slurred speech, poor coordination Significantly impaired
0.10 - 0.15% Drunk Major motor impairment, poor judgment Lack of coordination, blurred vision Extremely impaired
0.15%+ Danger Zone Severe impairment, possible blackout Loss of balance, nausea, vomiting Should not drive

About Blood Alcohol Content (BAC)

Blood Alcohol Content (BAC) is a measure of the amount of alcohol in your bloodstream. It's expressed as a percentage - for example, 0.08% means 0.08 grams of alcohol per 100 milliliters of blood. BAC is used to determine legal intoxication levels and to assess impairment from alcohol consumption.

BAC Calculation Formula

This calculator uses the Widmark formula, which is the standard method for estimating BAC:

BAC = (A / (W × r)) - (β × t)

  • A: Total alcohol consumed in grams
  • W: Body weight in grams
  • r: Widmark factor (0.68 for men, 0.55 for women)
  • β: Alcohol elimination rate (typically 0.015% per hour)
  • t: Time since first drink in hours

Standard Drink Equivalents

Drink Type Standard Size Alcohol Content Pure Alcohol Equivalent To
Regular Beer 355 ml (12 oz) 5% ABV 14 grams 1 standard drink
Light Beer 355 ml (12 oz) 4.2% ABV 11.8 grams 0.84 standard drinks
Wine 148 ml (5 oz) 12% ABV 14 grams 1 standard drink
Fortified Wine 89 ml (3 oz) 20% ABV 14 grams 1 standard drink
Distilled Spirits 44 ml (1.5 oz) 40% ABV 14 grams 1 standard drink
Malt Liquor 237 ml (8 oz) 7% ABV 13.3 grams 0.95 standard drinks

Factors Affecting BAC

  • Body Weight: More body mass dilutes alcohol, resulting in lower BAC
  • Gender: Women typically have higher BAC than men after consuming the same amount due to differences in body composition and enzymes
  • Metabolism: Rate at which your body processes alcohol (typically 0.015% per hour)
  • Food Consumption: Eating before or while drinking slows alcohol absorption
  • Drinking Speed: Consuming drinks quickly leads to higher peak BAC
  • Medications: Some medications can increase alcohol's effects
  • Tolerance: Regular drinkers may show fewer symptoms at the same BAC

Alcohol Elimination Rate

The average person metabolizes alcohol at a rate of about 0.015% BAC per hour. This means:

Starting BAC Time to 0.00% Time to 0.08% Time to 0.05% Notes
0.15% 10 hours 4.7 hours 6.7 hours Severely impaired
0.12% 8 hours 2.7 hours 4.7 hours Legally intoxicated
0.08% 5.3 hours 0 hours 2 hours Legal limit in US
0.05% 3.3 hours Already below 0 hours Legal limit in Europe

Limitations of BAC Calculations

  • BAC calculators provide estimates only - not exact measurements
  • Individual metabolism rates vary significantly (±30%)
  • Does not account for individual tolerance levels
  • May not accurately reflect impairment in regular heavy drinkers
  • Does not consider genetic factors affecting alcohol metabolism
  • Breathalyzer tests are the only accurate way to measure BAC

Important Safety Information

  • Never drink and drive - any amount of alcohol impairs driving ability
  • BAC calculators are for educational purposes only
  • If you're unsure if you're safe to drive, don't drive
  • Use designated drivers, taxis, or rideshare services when drinking
  • Buzzed driving IS drunk driving - impairment begins well before legal limits
  • Alcohol affects individuals differently - know your limits
  • Pregnant women should not consume alcohol
  • Mixing alcohol with medications can be dangerous
  • If you suspect alcohol poisoning (confusion, vomiting, seizures, slow breathing), call emergency services immediately

Legal Consequences

  • DUI/DWI charges can result in license suspension, fines, and jail time
  • Insurance rates typically increase significantly after a DUI
  • Commercial drivers have lower legal limits (0.04% in the US)
  • Underage drinkers face zero-tolerance policies (0.00-0.02% limits)
  • Refusing a breathalyzer test can result in automatic license suspension
  • DUI convictions stay on your record for years and affect employment opportunities
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