BAC Calculator
Estimate blood alcohol content using the Widmark formula.
📐 Widmark Formula: BAC = (Alcohol grams ÷ (Weight g × distribution ratio)) − (0.015 × hours). One standard drink ≈ 14g alcohol. Estimate only, not for legal or medical use.
BAC (Blood Alcohol Content/Concentration) is the percentage of alcohol in your bloodstream. It determines legal driving limits, impairment level, and health risk. In India, the legal driving BAC limit is 0.03% (30 mg per 100 ml of blood) — half of most Western countries. This calculator estimates your BAC based on drinks consumed, body weight, sex, and time elapsed, helping you understand when it is safe to drive after drinking.
📋 How to Use This Calculator
Enter your body weight, biological sex (men and women metabolise alcohol differently), number and type of drinks consumed, and time since you started drinking. The calculator estimates current BAC, time until you reach 0.00% BAC, and flags whether you are above the 0.03% Indian legal driving limit or above international limits like 0.05% and 0.08%.
💡 Key Facts & Information
Widmark formula: BAC = (Alcohol consumed in grams / (Body weight in grams × r)) − (Metabolism rate × Hours elapsed). Where r = 0.68 for men, 0.55 for women (body water distribution). Metabolism rate ≈ 0.015% per hour. Standard drink = 14g of pure alcohol = 330ml beer (5%) = 30ml whisky (40%) = 150ml wine (12%). One standard peg in India = 30ml (60ml is a large peg). BAC effects: 0.02–0.03%: mild relaxation. 0.05%: impaired judgment and coordination. 0.08%: reaction time significantly impaired — legal limit in US, UK. 0.10%: clearly impaired. 0.15%+: risk of blackout. 0.30%+: potentially fatal. Indian legal limit: 0.03% (30mg/100ml) under MV Act, Section 185 — stricter than most countries.