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What is Blood Alcohol Content?


Blood alcohol content (BAC), also called as blood alcohol concentration or blood alcohol level is a commonly used measure for alcohol intoxication for legal or medical purposes. It is usually expressed as a percentage of alcohol in the blood by volume. For instance, a BAC of 0.10 means that 0.10% (one tenth of one percent) of a person's blood is alcohol.


You will need to enter your body weight (in kilograms or pounds), the quantity of alcoholic beverage consumed (in ml. or fluid ounces), the percentage of alcohol in that beverage and the number of hours since you had those drinks.

You will find the percentage of alcohol on the label of your beverage's bottle. For some of the common beverages, the typical percentages are: Beer - 4%; Wine - 11%; Hard Liquor - 40%. Typical quantity in one drink of these beverages is: Beer - 12 fl.oz. (355 ml.); Wine - 4 fl.oz. (120 ml.); Hard Liquor - 1, 1.5. or 2 fl.oz. (30, 45 or 60 ml.) Please note that these are just typical percentages and quantities. You will need to find out the exact values in your case and enter those.

For example, if you had 3 small shots of whiskey (1 fl. oz. or 30 ml. each, with 40% alcohol content) over a period of 2 hours and you weigh 75 Kg. (165 lbs.), your BAC will be shown as .025%.


As the BAC level increases, it has the following effects on your behavior and body functions:

  • .020 - No noticeable effects in most people, but light to moderate drinkers begin to feel some effects
  • .040 - Most people begin to feel relaxed, less inhibited and joyous.
  • .060 - Judgment, depth perception and peripheral vision start getting impaired.
  • .080 - Definite impairment of muscle coordination and driving skills. This is the legal intoxication level in most states in the US.
  • .100 - Clear deterioration of reaction time, control and reflexes. Staggering and slurred speech gets are also noticeable.
  • .120 - Vomiting usually occurs.
  • .150 to .250 - Most people begin to experience memory blackouts.
  • .300 - Many people lose consciousness. Bladder function gets impaired.
  • .400 - Most people lose consciousness and some die.
  • .450 - Breathing stops. This is a fatal dose for most people.

The above information can be used as a guideline for controlling the amount of alcoholic beverages you consume.

The legal BAC limit for driving varies from state to state and country to country. The range is from 0 to 0.08% for most countries of the world. The legal BAC limit is 0.08% for most states of the United States and is 0.03% for most states of India. You should confirm the limit for your area of residence from your local authorities.

Please note that the BAC limit is useful for determining just the short term effects of alcohol consumption on your behaviour and body functions. Regular consumption of alcohol can have long term ill effects on your health. If you consume alcohol on a regular basis, please consult your health care provider for understanding the long term effects of alcohol consumption in your particular situation.


This tool is for information purposes only. Please contact your local law enforcement authorities for understanding the legal implications of consuming alcohol and your health care provider for understanding the short term and long term effects of alcohol consumption. This site is not responsible for any consequences of consumption of alcohol based on the use of this tool or any information given on this site.

Blood Alcohol Content (BAC) Calculator

To Calculate Blood Alcohol Level(BAL):
Quantity of Beverage
Alcohol Content Percentage
Hours you have been drinking Hours