About

Responsible consumption requires understanding how alcohol interacts with your unique physiology. This Blood Alcohol Content (BAC) Calculator utilizes the scientifically recognized Widmark formula to estimate the percentage of alcohol in your bloodstream. While not a replacement for a breathalyzer, it provides a critical baseline for understanding impairment.

Understanding BAC is vital for legal safety and personal well-being. Alcohol metabolism is influenced by weight, gender, and time. Even small amounts can affect reaction times and motor skills long before you reach the legal limit. This tool helps visualize the "sobering up" process, highlighting that time is the only true remedy for lowering BAC.

Formulas

The Widmark formula is the global standard for estimating BAC. It accounts for alcohol mass, body weight, and the gender-specific distribution ratio.

BAC = (A × 5.14W × r) − 0.015 × H

Where A is liquid ounces of alcohol consumed, W is weight in pounds, r is the distribution ratio (0.73 for men, 0.66 for women), and H is hours since the first drink.

Reference Data

BAC Level (%)	Physiological Effects	Driving Impairment
0.02 - 0.03%	Slight mood elevation, relaxation.	Decline in visual functions and multitasking.
0.04 - 0.05%	Warmth, minor impairment of judgment and memory.	Reduced coordination, difficulty steering, delayed response.
0.06 - 0.07%	Blunted feelings, disinhibition, extroversion.	Reduced information processing capability.
0.08% (Legal Limit)	Muscle coordination becomes poor (balance, speech, vision).	Short-term memory loss, speed control, reduced concentration.
0.10 - 0.12%	Clear deterioration of reaction time and control.	Inability to maintain lane position and brake appropriately.
0.15% +	Major loss of balance, vomiting likely.	Substantial impairment in vehicle control and auditory processing.

Frequently Asked Questions

The Widmark formula is highly accurate for averages but cannot account for individual metabolic rates, recent food consumption, or medication interactions. It is an estimation tool, not a medical diagnosis.

No. Caffeine may make you feel more alert, but it does not accelerate the metabolism of alcohol in the liver. Only time allows the body to process and eliminate alcohol.

On average, the human body eliminates alcohol at a rate of approximately 0.015 grams per 100 milliliters per hour (roughly one standard drink per hour).

Biological females typically have less body water and lower levels of the enzyme alcohol dehydrogenase compared to males of the same weight, resulting in a higher BAC for the same amount of alcohol consumed.