What is a standard drink in the United States?

A standard drink contains 14 grams (0.6 fl oz) of pure alcohol. This equals: 12 oz regular beer at 5% ABV, 5 oz wine at 12% ABV, or 1.5 oz distilled spirits at 40% ABV. Many craft beers, cocktails, and pour sizes exceed one standard drink — a pint of 8% craft beer is closer to 1.8 standard drinks.

How long does it take to sober up?

The average person metabolizes alcohol at a rate of 0.015-0.020% BAC per hour. At this rate, someone at 0.08% BAC would take 4-5 hours to reach 0.00%. Coffee, food, sleep, and water do not speed up alcohol metabolism — only time does.

What BAC level is legally drunk for driving?

In the U.S., 0.08% BAC is the legal limit for adults 21+. For drivers under 21, most states have a 0.02% or zero-tolerance limit. For commercial drivers (CDL holders), the limit is 0.04%. Many impaired driving experts argue meaningful impairment begins at 0.05% BAC.

How accurate is the Widmark formula?

The Widmark formula is an estimate with ±20% margin of error. It assumes average elimination rates and body water percentages. Factors that increase BAC beyond the formula's estimate: drinking on an empty stomach, certain medications, lack of sleep, smaller frame. Always err on the side of caution — if in doubt, don't drive.

❤️Health

Are You Safe to Drive? Estimate Your Blood Alcohol Content

How drunk are you right now?

What This Does

Blood alcohol content (BAC) is the concentration of alcohol in your bloodstream, expressed as a percentage. At 0.08% BAC — the legal limit for driving in all 50 U.S. states — your reaction time is roughly doubled, your ability to track moving objects is impaired, and your judgment is significantly compromised. At 0.15%, most people show visible intoxication. At 0.30%+, loss of consciousness is possible. The Widmark formula, developed in the 1930s and still the gold standard for BAC estimation, calculates blood alcohol concentration from the amount of alcohol consumed, the person's weight, biological sex, and time elapsed since first drink. Males and females metabolize alcohol differently due to differences in body water content — females typically reach higher BAC levels from the same number of drinks. This calculator uses the Widmark formula to estimate your BAC and shows your impairment progression over time as your body metabolizes the alcohol. It is intended for informational purposes — it cannot replace a breathalyzer or blood test. If there's any doubt about your ability to drive safely, the answer is simple: don't. Take a rideshare. Individual metabolic rates vary significantly based on food intake, medications, liver function, and other factors.

When Should You Use This?

→Estimating your approximate BAC after a specified number of drinks
→Understanding how long it will take for your BAC to reach zero
→Planning how many drinks keep you safely below the legal driving limit
→Educating yourself about impairment levels before social events involving alcohol
→Understanding the difference in alcohol metabolism between males and females

Example Scenario

Sarah, 140 lbs, has had 3 glasses of wine (each ~5 oz, 12% ABV) over 2 hours at a dinner party. Her estimated BAC using the Widmark formula: 0.07% — just below the 0.08% legal limit. However, her BAC peaked at 0.09% at the 1.5-hour mark. The calculator shows she'll be fully metabolized (0.00%) in about 1.5 more hours. She orders a coffee and waits before driving.

Educational Tool Only. BAC estimates carry ±20% variance due to food, medications, metabolism, and other factors. If there is any doubt about your ability to drive — do not drive. Not a substitute for a certified breathalyser.

🍺BAC Calculator

Blood Alcohol Content Estimator

Estimate your BAC using the Widmark formula. Enter your details and see your decay curve, drive-safe time, and per-drink scenarios. Results update live.

Body Weight

Number of Drinks

Drink Size (oz each)

Beer 12oz · Wine 5oz · Shot 1.5oz

Alcohol by Volume (%)

Beer ~5% · Wine ~12% · Spirits ~40%

Hours Since First Drink

Quick presets: