Blood Alcohol Content (BAC) is the percentage of alcohol in your blood. India's legal limit for driving is 0.03% - far stricter than the US (0.08%). This calculator uses the Widmark formula to estimate your BAC from drinks consumed and body weight.
Drinks consumed
Current BAC
5.958%
Peak BAC
7.458%
If just consumed
Hours to sober
4 hr
At 0.015%/hr elimination
Impaired - illegal in India
India's legal driving limit is 0.03% (30 mg per 100 ml of blood). Penalties: ₹10,000 fine + 6 months imprisonment for first offence; ₹15,000 + 2 years for repeat.
Standard drink ≈ 14 g of pure alcohol. The body eliminates alcohol at a near-constant rate of ~0.015% BAC per hour - coffee, water and food do not speed this up.
BAC estimates have wide error bars (±30%) due to individual differences in metabolism, food, hydration and genetics. Never use this calculator to decide whether to drive - if you've had any alcohol, take a cab.
Часть содержимого пока показывается на английском.
Blood Alcohol Content (BAC) measures the alcohol concentration in your bloodstream - typically expressed as a percentage. It's the legal definition of intoxication for driving in nearly every country. India enforces one of the world's strictest drink-driving limits at 0.03% BAC (30 mg/100ml). For context: the US limit is 0.08%, the UK 0.08% (England/Wales) or 0.05% (Scotland), most of Europe 0.05%. India's 0.03% means effectively that any meaningful alcohol consumption puts you over the legal limit.
This calculator uses the Widmark formula - the standard pharmacological model used since the 1930s for BAC estimation. It accounts for total alcohol consumed, body weight, gender (women have lower body water percentage, leading to higher BACs from the same alcohol), and time elapsed since drinking began (alcohol is eliminated by the liver at roughly 0.015% BAC per hour). Important: this is an estimate - individual variation due to food in stomach, drinking speed, genetics, and liver function means actual BAC can vary ±30% from prediction. Never use this to decide whether you can drive.
Pick your gender - body water content differs.
Enter your body weight in kg.
Add the drinks consumed - beer, wine, spirits, cocktails.
Enter how many hours have passed since your first drink.
Read your estimated current BAC and legal status.
The Widmark formula estimates peak BAC = (grams alcohol / (weight × distribution ratio)) × 100 / 1000. The distribution ratio is 0.68 for men, 0.55 for women - women hit higher BACs from the same alcohol. Alcohol is eliminated at ~0.015% BAC per hour.
Peak BAC% = (Grams alcohol / (Weight × r)) × 100/1000 Current BAC = max(0, Peak − 0.015 × Hours)
Widmark formula: Peak BAC% = (Grams of alcohol / (Body weight × r)) × 100/1000. Where r = 0.68 for men, 0.55 for women (distribution ratio based on average body water content). The result is a percentage. Current BAC = max(0, Peak BAC − 0.015 × Hours since drinking started). One standard drink contains roughly 13-14 g of pure alcohol - equivalent to one 330 ml beer at 5% ABV, one 150 ml wine at 12% ABV, or one 45 ml spirits shot at 40% ABV.
BAC effects on the body (rough guide, individual response varies): 0.02% - slight relaxation; 0.05% - judgment impaired; 0.08% - clear motor impairment (legally drunk in most Western countries); 0.10% - significant impairment, slurred speech; 0.15% - markedly impaired, vomiting possible; 0.30% - loss of consciousness possible; 0.40%+ - life-threatening alcohol poisoning. India's 0.03% legal threshold corresponds to early-stage relaxation - meaning the law catches even subtle impairment.
Time matters as much as alcohol amount. Liver elimination of alcohol is nearly constant at ~0.015% BAC per hour, regardless of body weight or how fast you drank. Coffee, cold showers, exercise, water - none of these speed up elimination. The only cure for high BAC is time. A 70 kg man who drinks 4 standard drinks reaches BAC ~0.08% after the last drink; it takes ~5 hours to clear back to 0.00%.
Alcohol consumed: 2 × 13 g = 26 g. Peak BAC = (26 / (70 × 0.68)) × 100/1000 = 0.0546%. After 2 hours: 0.0546 − 0.03 = 0.025% - just under India's 0.03% legal limit. But individual variation ±30% means you could easily be over. Don't drive.
Alcohol consumed: 180 × 0.13 × 0.789 (density) = 18.5 g. Peak BAC = (18.5 / (60 × 0.55)) × 100/1000 = 0.056%. After 1 hour: 0.056 − 0.015 = 0.041% - over India's 0.03% limit. Women hit higher BACs from the same alcohol; the gender adjustment matters.
0.03% (30 mg per 100 ml of blood). This is among the strictest in the world. The fine for first offence is up to ₹10,000 + 6 months imprisonment.
An estimate - Widmark is a population average. Individual variation is significant due to food in stomach, drinking speed, genetics and tolerance. Real BAC can be ±30% from the estimate.
For a 70 kg man, ~1 standard drink (13g alcohol) reaches 0.03% within 1 hour. For a 60 kg woman, even 1 drink can exceed it. The safe choice is zero before driving.
Yes. Drinking on a full stomach lowers peak BAC by 20-30% and slows the rise. But total alcohol absorbed is the same - only the timing changes.
About one standard drink per hour. The liver oxidises alcohol at a near-constant rate that you cannot speed up - coffee, water, cold showers don't help.
Absolutely not. The estimate has wide error bars. If you've had any alcohol, don't drive. Use a ride-hail app, designated driver or wait several hours and verify with a breathalyser.
Body composition, daily energy needs and pregnancy timelines all rest on formulas validated across millions of people, but no single number tells the whole story. The values from this calculator are point estimates with a known margin of error - body fat from skinfold or US Navy method has roughly a ±3% standard error compared to a DEXA scan, and BMR can vary ±10% person to person at the same height and weight. Use these numbers to track trends week over week, not to chase decimal precision day to day.
Pair this tool with the BMR, TDEE, calorie and macro calculators to turn a single measurement into an actionable plan. None of these tools are a substitute for a qualified doctor, registered dietitian or certified strength coach - but they remove the busywork so you spend more time on training and recovery, less on math.
The BAC Calculator is part of the Health & Fitness suite on Online Calculator Tools, alongside 6 related calculators. All tools share the same UI patterns, the same privacy-first rendering (nothing is sent to a server), and the same commitment to showing the formula and assumptions behind every result.
