BAC Calculator
Calculate Blood Alcohol Content with Widmark's formula
Calculate Your BAC
Personal Information
Alcohol Consumption
25g alcohol each
20g alcohol each
20g alcohol each
Total Alcohol: 0g
Time Since Drinking Started
Total time elapsed: 0 hrs 0 min
BAC Effects Reference
0.00% - 0.02% (Sober/Minimal)
No noticeable effects, normal behavior
0.02% - 0.05% (Light)
Relaxation, slight impairment of visual functions and divided attention
0.05% - 0.08% (Moderate)
Loss of muscle control, impaired judgment, lowered alertness, reduced coordination
0.08% - 0.10% (Legally Drunk)
Poor muscle coordination, impaired speech, self-control, reason, and memory
0.10% - 0.15% (Highly Intoxicated)
Poor coordination, slurred speech, slowed thinking
0.15%+ (Dangerous)
Potential vomiting, major loss of balance, risk of alcohol poisoning
BAC Quick Facts
Legal Limits
0.08% (USA), 0.05% (most countries), 0.00% (some jurisdictions)
Metabolism Rate
Average: 0.15‰ per hour (one drink per hour)
Gender Differences
Women typically have lower water content (55% vs 68% in men)
Standard Drinks
Large Beer
500ml at 5% ABV = 25g alcohol
Wine Glass
175ml at 12% ABV = 20g alcohol
Spirit Shot
50ml at 40% ABV = 20g alcohol
Important Warnings
Never Drink & Drive
Even small amounts of alcohol impair driving ability
Calculator Limitations
Estimates only. Individual factors vary significantly
Seek Help
If BAC is dangerously high, seek immediate medical attention
Understanding Blood Alcohol Content (BAC)
What is BAC?
Blood Alcohol Content (BAC) is the percentage of alcohol in your bloodstream. It's measured as mass of alcohol per volume of blood, typically expressed as a percentage (%) or per mille (‰).
Widmark's Formula
This calculator uses the Widmark equation: BAC = A/(bw × Wt) - (mr × t), where:
- A: Alcohol consumed (grams)
- bw: Body water ratio (0.68 male, 0.55 female)
- Wt: Body weight (kg)
- mr: Metabolism rate (0.15‰/hour)
- t: Time elapsed (hours)
Factors Affecting BAC
- •Body Weight: Heavier people have lower BAC for same alcohol amount
- •Gender: Women typically reach higher BAC due to lower water content
- •Food: Eating slows alcohol absorption
- •Time: Liver metabolizes alcohol at constant rate
- •Medications: Can affect alcohol metabolism
Medical Disclaimer
This calculator provides estimates only. Actual BAC varies significantly between individuals. Do not rely on this tool for driving decisions. When in doubt, don't drive. If you experience alcohol poisoning symptoms, seek immediate medical attention.