BAC Calculator

BAC is evaluated from Number of Standard Drinks, Body Weight and Biological Sex. The calculation reports Estimated BAC, Impairment Level and Hours Until BAC Reaches 0.

Results

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About the BAC Calculator

BAC is treated here as a quantitative relation between Number of Standard Drinks, Body Weight, Biological Sex and Hours Since You Started Drinking and Estimated BAC, Impairment Level, Hours Until BAC Reaches 0 and Legal Status for Driving.

The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
Widmark formula estimates BAC from alcohol consumed, body weight, and sex-based body water distribution factor. Subtract elimination rate (0.015%/hour) x hours elapsed. Individual metabolism, food, medication vary significantly.

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

Widmark formula estimates BAC from alcohol consumed, body weight, and sex-based body water distribution factor. Subtract elimination rate (0.015%/hour) x hours elapsed. Individual metabolism, food, medication vary significantly.

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: 170 lb male, 3 beers over 2 hours

Inputs

drinks: 3 weight_lbs: 170 sex: 1 hours_drinking: 2
Estimated BAC: 0.05%. Impairment Level: Moderate impairment - driving not safe. Hours Until BAC Reaches 0: 3.3 hours. Legal Status for Driving: Legal but impaired - avoid driving (Utah: 0.05% limit). Total Alcohol Consumed: 42 g. Calories from Alcohol: 294 cal

With Number of Standard Drinks = 3, Body Weight = 170, Biological Sex = 1 and Hours Since You Started Drinking = 2 as the stated inputs, the result is Estimated BAC = 0.05%, Impairment Level = Moderate impairment - driving not safe and Hours Until BAC Reaches 0 = 3.3 hours. Each value corresponds to the declared output fields.

Example 2: 130 lb female, 2 glasses of wine over 1.5 hours

Inputs

drinks: 2 weight_lbs: 130 sex: 0 hours_drinking: 1.5
Estimated BAC: 0.064%. Impairment Level: Moderate impairment - driving not safe. Hours Until BAC Reaches 0: 4.3 hours. Legal Status for Driving: Legal but impaired - avoid driving (Utah: 0.05% limit). Total Alcohol Consumed: 28 g. Calories from Alcohol: 196 cal

With Number of Standard Drinks = 2, Body Weight = 130, Biological Sex = 0 and Hours Since You Started Drinking = 1.5 as the stated inputs, the result is Estimated BAC = 0.064%, Impairment Level = Moderate impairment - driving not safe and Hours Until BAC Reaches 0 = 4.3 hours. Each value corresponds to the declared output fields.

Example 3: 220 lb male, 6 drinks over 3 hours (party scenario)

Inputs

drinks: 6 weight_lbs: 220 sex: 1 hours_drinking: 3
Estimated BAC: 0.079%. Impairment Level: Moderate impairment - driving not safe. Hours Until BAC Reaches 0: 5.3 hours. Legal Status for Driving: Legal but impaired - avoid driving (Utah: 0.05% limit). Total Alcohol Consumed: 84 g. Calories from Alcohol: 588 cal

With Number of Standard Drinks = 6, Body Weight = 220, Biological Sex = 1 and Hours Since You Started Drinking = 3 as the stated inputs, the result is Estimated BAC = 0.079%, Impairment Level = Moderate impairment - driving not safe and Hours Until BAC Reaches 0 = 5.3 hours. Each value corresponds to the declared output fields.

Example 4: 100 lb female, 4 drinks in 1 hour

Inputs

drinks: 4 weight_lbs: 100 sex: 0 hours_drinking: 1
Estimated BAC: 0.209%. Impairment Level: Severe: Unconscious, danger of death. Hours Until BAC Reaches 0: 14 hours. Legal Status for Driving: ILLEGAL to drive in all US states. Total Alcohol Consumed: 56 g. Calories from Alcohol: 392 cal

With Number of Standard Drinks = 4, Body Weight = 100, Biological Sex = 0 and Hours Since You Started Drinking = 1 as the stated inputs, the result is Estimated BAC = 0.209%, Impairment Level = Severe: Unconscious, danger of death and Hours Until BAC Reaches 0 = 14 hours. Each value corresponds to the declared output fields.

Common Use Cases

  • Estimate blood alcohol level after drinking
  • Understand how body weight affects BAC
  • Estimate time to sober up after drinking