Alcohol Metabolism Calculator
Estimate how long until you are sober based on your weight, drinks consumed, and time drinking.
See your estimated BAC over time.
How Alcohol Metabolism Rate Is Calculated
The liver metabolizes alcohol at a relatively fixed rate regardless of body size, tolerance, or coffee consumption. Understanding this rate helps estimate when blood alcohol returns to zero.
Alcohol Elimination Rate: The average person eliminates approximately 0.015–0.020 BAC (Blood Alcohol Concentration) per hour.
BAC Calculation (Widmark Formula):
BAC = (Alcohol consumed in grams) / (Body weight kg × r × 10)
Where r = gender factor:
- Males: r = 0.68
- Females: r = 0.55
Standard Drink = ~14g of pure alcohol (US standard):
- 355 mL (12 oz) beer at 5% = ~14g
- 148 mL (5 oz) wine at 12% = ~14g
- 44 mL (1.5 oz) spirits at 40% = ~14g
Worked Example: 80 kg male drinks 4 standard drinks over 2 hours:
- Alcohol consumed = 4 × 14g = 56g
- BAC = 56 / (80 × 0.68 × 10) = 56 / 544 = 0.103%
- Elimination over 2 hours: 0.016 × 2 = 0.032
- BAC at end of drinking: 0.103 − 0.032 = 0.071% (above 0.05% legal limit in most countries)
- Time to reach 0.00%: 0.071 / 0.016 = 4.4 more hours
Legal BAC Limits:
- Most of Europe, Australia: 0.05%
- USA, Canada, UK: 0.08%
- Sweden, Japan, many others: 0.02–0.03%
Nothing speeds up elimination: Not coffee, cold showers, food, or exercise. Only time works.