BAC Calculator

ATTENTION: Make sure you click "Calculate" after using The Adjuster to update the results.

This program shows how blood alcohol content is estimated using a refined verion of Widmark's BAC calculation formula. This newer formula is used by the National Highway Traffic Safety Administration. Unlike most BAC calculators, this one does not hide all the variables from you, so you know EXACTLY what it's calculating.

You can complete the equation using the 3 main inputs, that are color-coded in light blue.

BAC=23.36/(Weight*0.58*1000)*0.806*100*Alcohol consumed-(0.01789*Hours since consumed)

ABOUT

This program shows how blood alcohol content is estimated using a refined verion of Widmark's BAC calculation formula. This newer formula is used by the National Highway Traffic Safety Administration.

This formula has 12 sections: 3 boxes with variables that you must enter, 3 other boxes are the constants (4 since 'elimination' was split in 2), and 6 boxes that are values that are calculated using the variables and constants to get the BAC, which is the 6th and final calculation.

THE FORMULA

#1 Body water content in milliliters = Weight in kilograms * The percent of body weight that is water * 1000. note: percent of body weight that is water for male on average is 0.58, while it is 0.50 on average for women

#2 Grams of alcohol per milliliter of water in the body after the consumption of 1 ounce of alcohol = 23.36 grams (1 ounce) of alcohol / BODY WATER CONTENT in milliliters.

#3 Grams of alcohol per milliliter of blood = BODY ALCOHOL CONTENT * The percent of blood that is water. note: the percent of blood that is water is 0.806 on average

#4 Theoretical instantaneous BAC (Gram %) for 1 ounce of alcohol = BLOOD ALCOHOL CONTENT PER MILLILITER * 100. note: even though the blood alcohol content has already been found, the actual BAC is based on alcohol content per 100 milliliters of blood, rather than 1, that is why it must be multiplied by 100

#5 Actual instantaneous BAC = THEORETICAL BAC FOR 1 OUNCE * Ounces of pure alcohol actually consumed.

#6 Current BAC = ACTUAL INSTANTANEOUS BAC - ( Rate of metabolism * Hours since consumed. note: the average rate of metabolism for alcohol is 0.017 ounces an hour

BAC Effects

note: a drink in this chart is considered to be one ounce of liquor (a shot), four ounces of wine, or one 12 ounces of beer (can/bottle).

• .02
  • About one drink.
  • May feel a little warmth and relaxation.
• .04
  • About two drinks in an hour.
  • Most people feel relaxed, talkative, happy; the skin may flush.
  • Fine motor coordination is affected.
• .05
  • About two drinks in an hour.
  • First recognizable changes occur.
  • DWI convictions occur at this level at judge’s discretion.
• .08
  • About three drinks in an hour.
  • Muscle coordination is impaired and reaction time is slower.
  • There is sensory numbness in the face and lips.
  • Hands, arms and legs may tingle, then feel numb.
  • Legally intoxicated in ALL states. Illegal to drive.
• .10
  • About four to five drinks in an hour.
  • A clear deterioration of reaction time and muscle control.
  • Speech may be fuzzy and clumsiness may begin to appear.
• .15
  • Five to seven drinks in an hour.
  • Balance and movement are hazardously impaired.
• .20
  • Seven to ten drinks in an hour.
  • Motor and emotional controls are measurably affected.
  • Slurred speech, staggering, loss of balance and double vision are present.
• .30
  • Ten to fourteen drinks in an hour.
  • Lack of understanding of what is seen or heard.
  • Confusion, stupor, loss of consciousness.
• .40
  • Ten to fifteen drinks in an hour.
  • Unconsciousness. Threshold of coma. Lethal dose for 50% of the population.
• .50
  • Fourteen to twenty drinks in an hour.
  • Deep coma. Lethal dose for 75% of the population.

Percents Used

beer		6%
utah beer	3.5%
wine		12%