What is a "Standard Drink" in alcohol calculations?

In the United States and many health guidelines, one standard drink contains approximately 14 grams (0.6 fluid ounces) of pure ethanol. This equals one 12 oz (355ml) regular beer at 5% ABV, one 5 oz (150ml) glass of wine at 12% ABV, or one 1.5 oz (44ml) shot of 40% (80 proof) liquor.

What is the Widmark formula?

The Widmark formula computes BAC as: BAC = [Alcohol in grams / (Body Weight in grams × r)] × 100 - (β × Hours), where r is the gender body water constant (0.68 for men, 0.55 for women) and β is the metabolic elimination rate (typically 0.015% per hour).

Can coffee, cold showers, or exercise sober you up faster?

No. Only time allows your liver to metabolize alcohol. The human liver eliminates alcohol at a relatively constant rate of approximately 0.015% BAC per hour regardless of caffeine intake or cold showers.

Should I use this calculator to determine if I can drive?

No. This calculator provides educational mathematical estimates only. Individual metabolic rates, stomach food contents, medication, and hydration can significantly alter actual blood alcohol levels. Never drink and drive.

Is my personal health data saved?

No. Calculations are executed strictly inside your device web browser using JavaScript. No weight, gender, or drinking habits are stored or transmitted.

Blood Alcohol Content (BAC) Calculator

Estimate your Blood Alcohol Content (BAC) and time until sober using the scientific Widmark formula.

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Body Weight (kg)

Standard Drinks Consumed

Hours Since First Drink

Estimated Blood Alcohol Concentration (BAC)

0.052%

Mild Impairment / Lowered Inhibitions

Time Until 0.00% Sober

~3.5 hours

Legal Limit US/UK (0.08%)

✓ Below 0.08% Limit

Strict EU/AU Limit (0.05%)

✕ Over Strict Limit!

⚠️ Safety Disclaimer: This tool provides physiological estimates based on the Widmark formula for educational reference only. Individual rates vary by food intake, hydration, and genetics. Never drive after drinking.

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About Blood Alcohol Content (BAC) Calculator

The Blood Alcohol Content (BAC) Calculator uses the peer-reviewed Widmark formula to estimate the concentration of alcohol in your bloodstream. Factor in biological sex, body weight, number of standard alcoholic drinks consumed, and time elapsed to evaluate physical impairment and calculate when your body will metabolize all alcohol back to 0.00%.

How to use Blood Alcohol Content (BAC) Calculator

Select biological gender (affects body water distribution ratio $r$).
Enter your body weight in kilograms or pounds.
Specify the number of standard drinks consumed (1 standard drink = 14g pure alcohol / 12 oz 5% beer / 5 oz 12% wine / 1.5 oz 40% spirits).
Enter hours elapsed since your first drink.
View your estimated BAC percentage, impairment rating, and sober timeline.

Key features

Scientifically grounded Widmark physiological metabolic formula
Metric (kg) and Imperial (lbs) body weight measurement toggles
Calculates exact hours and minutes required to reach complete 0.00% sobriety
Compares current BAC against legal driving limits (0.05% EU/AU, 0.08% US/UK)

Frequently asked questions

What is a "Standard Drink" in alcohol calculations?: In the United States and many health guidelines, one standard drink contains approximately 14 grams (0.6 fluid ounces) of pure ethanol. This equals one 12 oz (355ml) regular beer at 5% ABV, one 5 oz (150ml) glass of wine at 12% ABV, or one 1.5 oz (44ml) shot of 40% (80 proof) liquor.
What is the Widmark formula?: The Widmark formula computes BAC as: BAC = [Alcohol in grams / (Body Weight in grams × r)] × 100 - (β × Hours), where r is the gender body water constant (0.68 for men, 0.55 for women) and β is the metabolic elimination rate (typically 0.015% per hour).
Can coffee, cold showers, or exercise sober you up faster?: No. Only time allows your liver to metabolize alcohol. The human liver eliminates alcohol at a relatively constant rate of approximately 0.015% BAC per hour regardless of caffeine intake or cold showers.
Should I use this calculator to determine if I can drive?: No. This calculator provides educational mathematical estimates only. Individual metabolic rates, stomach food contents, medication, and hydration can significantly alter actual blood alcohol levels. Never drink and drive.
Is my personal health data saved?: No. Calculations are executed strictly inside your device web browser using JavaScript. No weight, gender, or drinking habits are stored or transmitted.

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