Calculadora de Álcool no Sangue Online Grátis
Blood Alcohol Content by drink type with legal limits, time-to-sober chart and safety tips
Blood Alcohol Content (BAC) is the concentration of alcohol in your bloodstream, expressed as a percentage. This calculator estimates your BAC based on the number and type of drinks, your body weight, sex, and time since drinking — and shows you how long until you reach legal driving limits and full sobriety.
Frequently Asked Questions
Sobre Esta Calculadora
The Widmark formula, developed by Swedish scientist Erik Widmark in the 1920s, remains the foundation of BAC estimation in forensic science and medicine. It uses a volume of distribution factor (r) that differs between males and females because women generally have proportionally less body water — causing alcohol to be more concentrated in their bloodstream at the same intake.
BAC affects different people differently depending on tolerance, food intake, hydration, genetics, and medications. This calculator provides estimates based on population averages — individual BAC can vary by ±30% from these figures.
Even at BAC levels below legal driving limits, reaction time and judgment are measurably impaired from the very first drink. The "legal limit" defines criminal liability, not the threshold of impairment. The only reliable way to sober up is time — coffee, food, and water do not accelerate alcohol metabolism.
Estime o teor de álcool no sangue (TAS) com base nas bebidas ingeridas.
Fórmula
BAC = (Alcohol grams / (Body weight × r)) - (0.015 × Hours) r = 0.68 for men, 0.55 for women
Exemplo Resolvido
BAC estimate for a 70 kg man after 3 beers in 2 hours
Entradas:
- Sex: Male
- Body weight: 70 kg
- Drinks: 3 standard beers (355 ml, 5% ABV each)
- Time elapsed: 2 hours
Passo a Passo:
- Alcohol in each beer: 355 ml × 0.05 × 0.789 g/ml = 14.0 g per beer
- Total alcohol: 3 × 14.0 = 42.0 g
- Distribution factor (r) for men = 0.68
- Widmark formula (peak BAC): 42.0 / (70,000 g × 0.68) = 0.000883 = 0.088%
- Subtract elimination: 0.015% × 2 hours = 0.030%
- Estimated BAC after 2 hours: 0.088% − 0.030% = 0.058%
Dicas
- Your liver clears ~0.015% BAC per hour. A BAC of 0.08% takes 5-6 hours to clear.