Estimate your BAC and know when it is safe to drive
BAC is the concentration of alcohol in your bloodstream, expressed as a percentage. A BAC of 0.05% means 0.05 grams of alcohol per 100 ml of blood. Even small amounts of alcohol impair judgment and reaction time before you feel obviously drunk โ this is one of the most dangerous aspects of drink driving.
The Widmark formula is the standard method for estimating BAC. It considers your body weight, gender (because women have a lower body water percentage than men and therefore reach higher BAC with the same drinks), number of drinks consumed, and time elapsed for the liver to process the alcohol.
0.01-0.03%: Mild relaxation, slight mood elevation. Most people don't feel obviously impaired but reaction time is already slightly affected.
0.04-0.06%: Relaxed, lowered inhibitions, impaired judgment beginning. This is around India's legal driving limit for most drivers (0.05%).
0.07-0.09%: Noticeable impairment of balance, speech and reaction time. Driving is significantly dangerous at this level.
0.10-0.15%: Clear impairment. Slurred speech, poor coordination, significantly impaired judgment.
0.16-0.30%: Severe impairment, possible blackouts, vomiting risk.
Above 0.30%: Risk of alcohol poisoning, loss of consciousness, potentially fatal.
Under the Motor Vehicles Act, the permissible BAC limit in India is 30 mg per 100 ml blood (0.03%) for professional or commercial drivers, and 50 mg per 100 ml (0.05%) for private vehicle drivers. Driving above these limits can result in imprisonment up to 6 months, fine up to Rs 10,000, or both for a first offence. Penalties are significantly higher for repeat offences.
The only truly safe BAC for driving is zero. Even at the legal limit, your driving ability is compromised. A taxi or cab is always the better choice after drinking.