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Blood Alcohol Calculator (BAC)

Patient weight:kglbs
Percentof body capable of absorbing alcohol (Usual ranges): 
Time spent drinking ortime elapsed.  Hours (Enter zero for acute ingestion.)
Volumeconsumed:mlFluid oz Numberof drinks:See table below forcommon volumes and percentages.

You are watching: Bac can be determined solely from the amount of alcoholic beverages consumed.

Alcoholunits: percent (ABV)proof (e.g. 50% or 100 proof)

Disclaimer: This is only a rough estimatebased on population averages and does not take into account existing diseasestates, drug interactions, or age.

Typical Volumes and Concentration


Background Info

Definition: Blood alcoholconcentration (BAC) is the amount of alcohol in an individual’s body,measured by the weight of the alcohol in a volume of blood. TheBAC limit determines the maximum amount of alcohol that can be consumedbefore it is illegal to operate a motor vehicle on a public road.This program summarizes some of the effects that may be seen based onthe calculated blood alcohol concentration. Generally, there is widevariation in alcohol tolerance among individuals and therefore thepredominant effects may vary. Theeffects of alcohol intoxication are greatly influenced by individualvariations among users. Some users may become intoxicated at a muchlower blood alcohol concentration. Impairment can result fromany level above 0.00. Also, the degree of impairmentrises dramatically as the BAC rises.An individual’s BAC depends uponthat person’s gender, weight, metabolism, time period over which thealcohol was consumed and the amount of food in the stomach prior todrinking. Although a person’s BAC can be estimated, the levelcannot be determined solely by the number of drinks consumed, and cannotbe precisely calculated by a person’s height and weight. In single-vehicle crashes, the relativerisk of a driver with BAC between .08 and .10 is at least 11 timesgreater than for drivers with a BAC of zero, and 52 times greater foryoung males. Further, many studies have shown that even small amounts ofalcohol can impair a person’s ability to drive. ABW versus ABV??The concentration of alcohol in a beverage is usually stated as thepercentage of alcohol by volume (ABV) or as proof. Some tables maylist the alcohol concentration as ABW (alcohol by weight).To convert ABW to ABV, you must divide the ABW by the specific gravityof alcohol which is ~0.787Therefore 4.3% ABW/ 0.787 = 5.46% ABV. Alternatively you canmultiply the ABW (alcohol by weight) by 1.271.Summary: ABV = ABW / 0.787 or ABV = ABW x 1.271

Alcohol Content


AlcoholContent (in Percent) of Selected Beverages
BeverageAlcohol Content (%)Usual Serving size
Beers (lager)3.2 - 4.01 can/bottle = 355 ml = 12 fl. oz.
Ales4.51 can/bottle = 355 ml = 12 fl.oz.
Porter6.01 can/bottle = 355 ml = 12 fl.oz.
Stout6.0 - 8.01 can/bottle = 355 ml = 12 fl.oz.
Malt Liquor3.2 - 7.01 can/bottle = 355 ml = 12 fl.oz.
Sake14.0 - 16.0one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)
Table wines7.1 - 14.0one glass = 148 ml = 5 fl. oz.
Sparkling wines / Champagne 8.0 - 14.0one glass = 148 ml = 5 fl. oz.
Fortified wines14.0 - 24.0one glass = 148 ml = 5 fl. oz.
Aromatized wines15.5 - 20.0one glass = 148 ml = 5 fl. oz.
Brandies40.0 - 43.0one glass = 148 ml = 5 fl. oz.
Whiskies40.0 - 75.0one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)
Vodkas40.0 - 50.0one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)
Gin40.0 - 48.5one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)
Rum40.0 - 95.0one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)
Tequila45.0 - 50.5one shot = 44 ml = 1.5 fl. oz. (Range:1.25 to 1.5 fl.oz. or 37 - 44 ml)

AlcoholContent of Some Typical DrinksMixed drinks are based on typical drink recipes using 80proof liquor. The amount of alcohol in actual mixed drinksmay vary.

See more: How Many Newtons Is A Punch, What Is The Average Force Of A Punch

DrinkAlcohol Content
Manhattan1.15 oz. (34 ml)
Dry Martini1.00 oz. (30 ml)
Malt liquor -12oz. (355 ml)0.71 oz. (21 ml)
Airline miniature0.70 oz. (21 ml)
WhiskeySour/Highball0.60 oz. (18 ml)
Table Wine - 5 oz.(148 ml)0.55 oz. (16 ml)
Beer - 12 oz. (355ml)0.54 oz. (16 ml)
Reduced AlcoholBeer0.28 oz. (8 ml)

Reference(s)

Drug Abuse Handbook. 2nd edition. Edited by Steven B. Karch. CRCPress/Taylor & Francis (Boca Raton), 2007.Gullberg, R.G. and Jones, A.W., "Guidelines for Estimating the Amountof Alcohol Consumed From a Single Measurement of Blood AlcoholConcentration: Re-Evaluation of Widmark"s Equation", Forensic ScienceInternational, Vol.69, 1994Widmark, E.M.P., Principles and Applications of Medicolegal AlcoholDetermination, Davis, CA: Biomedical Publications, 1981, pp. 107-108.