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Friends clinking drink glasses in a bar. Credit: @jcomp / Freepik

What Is Blood Alcohol Concentration (BAC)?

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Blood Alcohol Concentration (BAC) refers to the percent of alcohol (ethyl alcohol or ethanol) in a person's blood stream. A BAC of .10% means that an individual's blood supply contains one part alcohol for every 1000 parts blood.

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Beer bottle texture. Credit: @banjongseal324 / Freepik

Factors That Impact BAC

  • Number of standard drinks 
  • Amount of time in which drinks are consumed
  • Body weight
  • Water composition
  • Enzyme production and levels
  • Sex assigned at birth and corresponding hormone levels
  • Medications
  • Food 
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Standard Drink

One Standard Drink

  • One 12 oz. regular beer (4.5-6% alcohol)
  • One 12oz. White Claw (5% alcohol)
  • One 7 oz. malt liquor (7% alcohol)
  • One 5 oz. glass of wine (12% alcohol)
  • One 1.5 oz. shot of hard liquor (40% alcohol)
  • One-third jigger (.5 oz.) of Everclear (95% alcohol)

More Than One Standard Drink

  • One 16 oz. cup of beer = 1.4 drinks
  • One 40 oz. beer = 3.6 drinks
  • One 22 oz. malt liquor = 3 drinks
  • One 12 oz. glass of wine = 2.9 drinks
  • One 12 oz. margarita = 2–4 drinks, depending on ingredients
  • One 12 oz. cup of trashcan punch = 4–10 drinks, depending on ingredients
"Too Much to Drink" concept art. Credit: iqoncept / Deposit Photos

Blood Alcohol Content (BAC) Calculator

Blood Alcohol Content, or BAC, refers to the percentage of alcohol in a person's bloodstream, and can be measured within 30-70 minutes after drinking. Contrary to popular belief, nothing can lower BAC except time; coffee, cold showers, and chugging glasses of water will not help you sober up any faster. Curious what your BAC might be? Use our calculator to estimate, but don't forget that everyone metabolizes alcohol (beer, wine, liquor) differently. Our calculator can give you an approximate BAC level, but do not rely upon it to determine if you're fit to drive or work.

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Effects of Alcohol at Various Blood Alcohol Concentration Levels

BAC Physical and Mental Effects
.01 - .03 No apparent effects. Slight mood elevation. In California, you will test as legally impaired at .01% BAC if you are under 21. It is illegal to drive or bike at this level.
.04 - .06 Feeling of relaxation. Sensation of warmth. Minor impairment of reasoning and memory.
.07 - .09 Mild impairment of balance, speech, vision and control. In California, you will test as legally impaired at .08% BAC if you are over 21. It is illegal to drive or bike at this level.
.10 - .12 Significant impairment of motor coordination and loss of judgment. Speech may be slurred.
.13 - .15 Gross impairment of motor control. Blurred vision and major loss of balance. Onset of dysphoria (anxiety, restlessness).
.16 - .20 Dysphoria predominates. Nausea may appear. Drinker has the appearance of “sloppy drunk.”
.25 - .30 Severe intoxication. Needs assistance walking. Mental confusion. Dysphoria with nausea and some vomiting.
.35 - .40 Loss of consciousness. Brink of coma.
.40 and up Onset of coma. Likelihood of death due to respiratory failure.