Blood Alcohol Concentration (BAC) Calculator

Estimate your blood alcohol content and time to sober up based on drinks consumed.

Drink Information

hours minutes
Amount of Alcohol Consumed
Type Amount Size ABV
Beer
Wine
Liquor
Other
Result

BAC is around 0.000%.

It will take around 0 more hours to reach 0%.

Enter your information and click Calculate.

BAC Risk Level

Sober Mild Moderate High Severe

* The results are meant for educational purposes only and are not intended to replace the medical advice of doctors or health care providers. Please consult your health care provider regarding specific health conditions. Never drink and drive.

Complete BAC Calculator Guide & Information

1. What is Blood Alcohol Concentration (BAC)?

Blood Alcohol Concentration (BAC) is the percentage of alcohol (ethyl alcohol or ethanol) in a person's bloodstream. A BAC of 0.10% means that an individual's blood supply contains one part alcohol for every 1,000 parts blood. BAC is used legally and medically to determine the degree of alcohol intoxication.

In most jurisdictions, the legal limit for driving is 0.08% BAC. However, impairment begins well before reaching this threshold. Even at 0.02-0.05%, reaction time, judgment and coordination begin to decline.

2. Calculation Formula (Widmark Equation)

Standard Widmark Formula:
BAC = (A × 5.14 / (W × r)) − (0.015 × H)

Where:
A = total alcohol consumed in US fluid ounces
W = body weight in pounds
r = Widmark factor: 0.68 for males, 0.55 for females
H = hours elapsed since first drink
0.015 = average elimination rate per hour

Metric version:
BAC = (A / (W × r)) × 100 − (0.015 × H)
A = alcohol in grams, W = weight in kilograms

The formula was developed by Swedish physician Erik Widmark in the 1930s and remains the standard for estimating BAC. The gender difference (r factor) reflects differences in body water composition — men typically have a higher percentage of water per pound of body weight than women.

3. BAC Levels & Effects

BAC Range Level Typical Effects
0.00 – 0.02% Minimal / Subclinical Feeling of relaxation, mild euphoria. No obvious impairment.
0.02 – 0.05% Mild Relaxation, lowered inhibitions, slight impairment of judgment and attention.
0.05 – 0.08% Moderate Pleasant euphoria, reduced reaction time, impaired peripheral vision and depth perception. Legally impaired for driving in many countries at 0.08%.
0.08 – 0.15% High Significant impairment of motor coordination, balance, speech and vision. Judgment and self-control are noticeably reduced. Nausea may occur.
0.15 – 0.30% Severe Marked ataxia, slurred speech, blurred vision, dizziness, vomiting. Blackouts are common. Significant loss of mental function.
0.30 – 0.40% Very Severe Loss of consciousness, stupor. Risk of respiratory depression and death from alcohol poisoning.
0.40% + Lethal Coma and death from respiratory arrest. LD50 for alcohol is approximately 0.40% BAC.

4. Alcohol Metabolism & Elimination

Alcohol is eliminated from the body at a relatively constant rate, primarily through metabolism in the liver. The average elimination rate is approximately 0.015% BAC per hour, but this can vary between individuals from about 0.010% to 0.020% per hour based on:

5. Standard Drink Equivalents

Beverage Typical Serving ABV Pure Alcohol
Beer (regular)12 oz (355 ml)5%0.6 oz / 14 g
Wine (table)5 oz (148 ml)12%0.6 oz / 14 g
Distilled spirits1.5 oz (44 ml)40%0.6 oz / 14 g
Malt liquor12 oz (355 ml)7%0.84 oz / 25 g
Fortified wine3.5 oz (104 ml)17%0.6 oz / 17 g

One standard drink contains approximately 0.6 fluid ounces (14 grams) of pure ethyl alcohol.

6. Factors Affecting BAC

7. Input & Control Definitions

8. Important Warnings & Limitations

9. References

1. Widmark EMP. "Principles and applications of medicolegal alcohol determination." 1932.
2. National Highway Traffic Safety Administration (NHTSA). "Alcohol and highway safety."
3. National Institute on Alcohol Abuse and Alcoholism (NIAAA). "Alcohol metabolism: an update." 2007.
4. Jones AW. "Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic toxicology." Forensic Science International. 2010.
5. American Medical Association. "Alcohol and health."
6. Centers for Disease Control and Prevention (CDC). "Blood alcohol concentration (BAC) levels."