Blood Alcohol Calculator (BAC)
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|
Patient weight:
|
|
Percent
of body capable of absorbing alcohol (Usual ranges):
|
Time spent drinking or
time elapsed.
Hours (Enter zero for acute ingestion.)
|
Volume
consumed:
Number
of drinks:
See table below for
common volumes and percentages. |
|
Alcohol
units: (e.g. 50% or 100 proof) |
|
|
Disclaimer: This is only a rough estimate
based on population averages and does not take into account existing disease
states, drug interactions, or age. |
Typical Volumes and Concentration
|
| Beverage
|
Usual Volume |
Usual
Concentration |
|
Beer
|
12 or 16
oz
|
5.0
%
|
|
Wine
|
2.5 or
5oz
|
12.0
%
|
| 1
Shot |
1.25
oz |
80
proof |
|
Background Info
|
Definition: Blood alcohol
concentration (BAC) is the amount of alcohol in an individual’s body,
measured by the weight of the alcohol in a volume of blood. The
BAC limit determines the maximum amount of alcohol that can be consumed
before it is illegal to operate a motor vehicle on a public road.
This program summarizes some of the effects that may be seen based on
the calculated blood alcohol concentration. Generally, there is wide
variation in alcohol tolerance among individuals and therefore the
predominant effects may vary. The
effects of alcohol intoxication are greatly influenced by individual
variations among users. Some users may become intoxicated at a much
lower blood alcohol concentration. Impairment can result from
any level above 0.00. Also, the degree of impairment
rises dramatically as the BAC rises.
An individual’s BAC depends upon
that person’s gender, weight, metabolism, time period over which the
alcohol was consumed and the amount of food in the stomach prior to
drinking. Although a person’s BAC can be estimated, the level
cannot be determined solely by the number of drinks consumed, and cannot
be precisely calculated by a person’s height and weight.
In single-vehicle crashes, the relative
risk of a driver with BAC between .08 and .10 is at least 11 times
greater than for drivers with a BAC of zero, and 52 times greater for
young males. Further, many studies have shown that even small amounts of
alcohol can impair a person’s ability to drive.
ABW versus ABV??
The concentration of alcohol in a beverage is usually stated as the
percentage of alcohol by volume (ABV) or as proof. Some tables may
list the alcohol concentration as ABW (alcohol by weight).
To convert ABW to ABV, you must divide the ABW by the specific gravity
of alcohol which is ~0.787
Therefore 4.3% ABW/ 0.787 = 5.46% ABV. Alternatively you can
multiply the ABW (alcohol by weight) by 1.271.
Summary: ABV = ABW / 0.787 or
ABV = ABW x 1.271 |
Alcohol Content
|
| Alcohol
Content (in Percent) of Selected Beverages |
| Beverage |
Alcohol Content (%) |
Usual Serving size |
| Beers (lager) |
3.2 - 4.0 |
1 can/bottle = 355 ml = 12 fl. oz. |
| Ales |
4.5 |
1 can/bottle = 355 ml = 12 fl.oz. |
| Porter |
6.0 |
1 can/bottle = 355 ml = 12 fl.oz. |
| Stout |
6.0 - 8.0 |
1 can/bottle = 355 ml = 12 fl.oz. |
| Malt Liquor |
3.2 - 7.0 |
1 can/bottle = 355 ml = 12 fl.oz. |
| Sake |
14.0 - 16.0 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
| Table wines |
7.1 - 14.0 |
one glass = 148 ml = 5 fl. oz. |
| Sparkling wines / Champagne |
8.0 - 14.0 |
one glass = 148 ml = 5 fl. oz. |
| Fortified wines |
14.0 - 24.0 |
one glass = 148 ml = 5 fl. oz. |
| Aromatized wines |
15.5 - 20.0 |
one glass = 148 ml = 5 fl. oz. |
| Brandies |
40.0 - 43.0 |
one glass = 148 ml = 5 fl. oz. |
| Whiskies |
40.0 - 75.0 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
| Vodkas |
40.0 - 50.0 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
| Gin |
40.0 - 48.5 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
| Rum |
40.0 - 95.0 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
| Tequila |
45.0 - 50.5 |
one shot = 44 ml = 1.5 fl. oz. (Range:
1.25 to 1.5 fl.oz. or 37 - 44 ml) |
Alcohol
Content of Some Typical Drinks
Mixed drinks are based on typical drink recipes using 80
proof liquor. The amount of alcohol in actual mixed drinks
may vary.
|
| Drink |
Alcohol Content |
| Manhattan |
1.15 oz. (34 ml) |
| Dry Martini |
1.00 oz. (30 ml) |
| Malt liquor -12
oz. (355 ml) |
0.71 oz. (21 ml) |
| Airline miniature |
0.70 oz. (21 ml) |
| Whiskey
Sour/Highball |
0.60 oz. (18 ml) |
| Table Wine - 5 oz.
(148 ml) |
0.55 oz. (16 ml) |
| Beer - 12 oz. (355
ml) |
0.54 oz. (16 ml) |
| Reduced Alcohol
Beer |
0.28 oz. (8 ml) |
|
Reference(s)
|
Drug Abuse Handbook. 2nd edition. Edited by Steven B. Karch. CRC
Press/Taylor & Francis (Boca Raton), 2007.
Gullberg, R.G. and Jones, A.W., "Guidelines for Estimating the Amount
of Alcohol Consumed From a Single Measurement of Blood Alcohol
Concentration: Re-Evaluation of Widmark's Equation", Forensic Science
International, Vol.69, 1994
Widmark, E.M.P., Principles and Applications of Medicolegal Alcohol
Determination, Davis, CA: Biomedical Publications, 1981, pp. 107-108. |
