What Is a BAC Calculator?
A BAC (Blood Alcohol Concentration) calculator estimates the level of alcohol in your bloodstream based on your drinking pattern, body weight, and gender. This tool helps illustrate how various factors influence alcohol impairment for educational awareness purposes.
How to Use This BAC Calculator
- Enter the number of standard drinks consumed (1 drink = 14 g of pure alcohol).
- Enter your body weight in kilograms.
- Enter the number of hours since your first drink.
- Enter your gender (type “male” or “female”).
- Click “Calculate” to view your estimated BAC, impairment level, and estimated time to sobriety.
Key Concepts
BAC is measured as grams of alcohol per 100 mL of blood, typically expressed as a percentage. The liver metabolizes alcohol at roughly 0.015% per hour. Factors affecting BAC include body weight, body water percentage, food consumption, metabolic rate, and medications. Legal BAC limits for driving vary globally from 0.00% to 0.08%. This calculator is for informational purposes only—never rely on it for safety decisions.
BAC = (Alcohol(g) ÷ (Body Weight(g) × r)) − (0.015 × Hours)
r = 0.68 (male) / 0.55 (female)
Frequently Asked Questions
What counts as a “standard drink”?
In the U.S., one standard drink contains about 14 grams of pure alcohol: roughly 355 mL of beer (5%), 150 mL of wine (12%), or 44 mL of spirits (40%). Standards differ by country.
Does eating food lower BAC?
Eating before or while drinking slows alcohol absorption, potentially resulting in a lower peak BAC. However, once absorbed, food does not speed up alcohol metabolism. The total amount of alcohol consumed still determines overall BAC.
Should I use this to judge if I can drive?
Absolutely not. BAC estimates are approximations with significant individual variability. Impairment can occur well below legal limits. If you have consumed any alcohol, arrange alternative transportation.