About

Understanding your Blood Alcohol Content (BAC) is a critical aspect of personal safety and responsible decision-making. Alcohol metabolism varies significantly between individuals based on physiology, making "counting drinks" an unreliable method for determining sobriety. This tool utilizes the Widmark Formula, the forensic standard for estimating alcohol intoxication levels.

This calculator is essential for anyone planning to drive or operate machinery after a social event. By inputting specific variables such as body weight, gender, and the type of alcohol consumed, it provides an estimate of current BAC and, crucially, the "Time to Zero"—the duration required for your body to fully metabolize the alcohol. Disclaimer: This tool is for educational purposes only. Metabolism is complex, and real-world BAC can fluctuate. Never drink and drive.

Formulas

The Widmark formula calculates BAC by determining the mass of alcohol consumed relative to total body water.

BAC = (A × 5.14W × r) − 0.015 × H

Where:
A = Liquid oz alcohol consumed × %ABV
W = Weight in lbs
r = Widmark factor (0.73 men, 0.66 women)
H = Hours since drinking began

Reference Data

Beverage Type	Standard Volume	ABV %	Pure Alcohol (g)
Light Beer	355 ml (12 oz)	4.2%	~11.8g
Standard Beer	355 ml (12 oz)	5.0%	~14.0g
IPA / Craft Beer	355 ml (12 oz)	7.0%	~19.6g
Table Wine (Red/White)	150 ml (5 oz)	12.0%	~14.2g
Fortified Wine	90 ml (3 oz)	18.0%	~12.8g
Hard Liquor (Vodka/Gin)	45 ml (1.5 oz)	40.0%	~14.2g
Cask Strength Whiskey	45 ml (1.5 oz)	55.0%	~19.5g
Liqueur	45 ml (1.5 oz)	20.0%	~7.1g

Frequently Asked Questions

The liver metabolizes alcohol at a constant rate of approximately 0.015 g/100mL per hour (about one standard drink per hour). Coffee, cold showers, or food cannot speed up this process; only time works.

The Widmark Factor represents the distribution of water in the body. Since alcohol dissolves in water, individuals with more body water (typically men, who have more muscle mass) will have a lower BAC for the same amount of alcohol compared to individuals with less body water.

It is a rough generalization. A small person drinking a high-ABV craft beer will exceed the driving limit much faster than a large person drinking a light beer, even if both stick to 'one drink per hour'.

Food in the stomach can slow the *absorption* of alcohol into the bloodstream, effectively lowering the peak BAC, but it does not eliminate the alcohol that has already been absorbed. It delays the peak rather than preventing intoxication.