Safety

Blood Alcohol Concentration Calculator

Model BAC based on the Widmark formula, track elimination over time, and export impairment summaries. Built for event planners, educators, and responsible hosts.

Current BAC

0.000%

Widmark estimate

Alcohol grams consumed

14.0 g

Across 1 drinks

Metabolism window

0 hrs

Estimated time to reach 0.00%

Mild mood elevation, minimal impairment

BAC curve (next 12 hours)

Track elimination assuming 0.015% reduction per hour.

Past

Future

Understanding BAC

Blood alcohol concentration (BAC) is the percentage of alcohol present in the bloodstream. Most countries define legal intoxication for driving between 0.05% and 0.08%. This calculator uses the Widmark equation and assumes steady metabolism to approximate BAC for educational purposes only—never use the results to determine fitness to drive.

Widmark formula: BAC = (A / (r × body weight)) × 100 − β × time. A is grams of alcohol, r is the alcohol distribution ratio (0.68 men, 0.55 women), and β is the elimination constant (0.015% per hour on average).

Alcohol absorption variables

Full stomach slows absorption; peak BAC occurs later compared to fasting state.
Carbonated mixers and higher-proof spirits speed up absorption.
Body fat percentage affects distribution volume—lean bodies dilute alcohol more efficiently.
Medications may interact with alcohol and compound impairment.

Effects by BAC

BAC range	Impairment
0.00 - 0.02	Mild mood elevation, minimal impairment
0.02 - 0.04	Relaxation, loss of shyness, reduced alertness
0.04 - 0.06	Exaggerated behavior, reduced coordination
0.06 - 0.08	Speech, balance, reaction time decline
0.08 - 0.15	Substantial impairment, poor judgment, gross motor loss
0.15 - 0.30	Vomiting, major loss of balance, possible blackouts
> 0.30	Risk of loss of consciousness, respiratory failure

Harm reduction tips

Alternate alcoholic beverages with water or electrolyte drinks.
Track servings—standard pours are smaller than most bar glasses.
Arrange transportation before drinking. Breathalyzer checkpoints often appear near nightlife districts.
Pregnant individuals and certain medical conditions should avoid alcohol entirely.

This tool is informational. Consult healthcare providers for personalized advice.