Loading calculators...
Fetching calculator categories and tools for this section.
Preparing tools and content for you. This usually takes a second.
Fetching calculator categories and tools for this section.
Estimate blood alcohol concentration (BAC) from beer, wine, liquor, or custom drinks using the Widmark formula. Enter weight, sex, and hours since drinking for approximate BAC, impairment level, and time to sober. Pair with our standard drink calculator — not a substitute for breath or blood testing.
Last updated: June 4, 2026
Blood Alcohol Concentration
0.025%
Legal Status
Under 0.08% US per se limit for 21+ — impairment may still exist
Impairment
Subtle effects detectable with special tests
Estimated Time to Sober
1.6 hours
Important Warning
BAC calculations are estimates. Do not drive if your BAC is 0.08% or above. Individual metabolism varies. Always use a designated driver or alternative transportation.
2×330 ml beer, 5% · 70 kg male · 2 h
0.025%
~1.6 h to ~0% on model
4 beers · 75 kg male · 1 h
0.087%
At or above 0.08% — do not drive (US 21+)
3 wine glasses · 60 kg female · 2 h
0.099%
Near per se limit — do not drive
4×50 ml shots, 40% · 80 kg male · 30 min
0.109%
~7.2 h to ~0% on model
Ethanol per drink (grams) ≈ ml × (ABV ÷ 100) × 0.789
Peak BAC% = (total ethanol g ÷ (weightg × r)) × 100
BAC now = Peak BAC% − (0.015 × hours)
r ≈ 0.68 (male), 0.55 (female). β ≈ 0.015% BAC eliminated per hour (average).
| Beverage | Typical pour | ABV | Ethanol |
|---|---|---|---|
| US standard drink (reference) | — | — | 14 g pure alcohol |
| Regular beer | 12 fl oz (355 ml) | ~5% | ~14 g |
| Wine | 5 fl oz (148 ml) | ~12% | ~14 g |
| Distilled spirits | 1.5 fl oz shot (44 ml) | ~40% | ~14 g |
| Jurisdiction | Limit | Notes |
|---|---|---|
| United States (21+ drivers) | 0.08% BAC | Per se DUI in all states; lower in some circumstances |
| US under 21 | 0.00 – 0.02% (state zero-tolerance) | Any detectable alcohol often illegal for minors |
| Commercial drivers (US) | 0.04% BAC | FMCSA standard for CDL holders |
| Many EU countries | 0.05% BAC common | Some 0.02% for new drivers; verify locally |
| BAC | Typical behavior | Impairment |
|---|---|---|
| 0.00 – 0.02% | May appear normal | Subtle effects on some tests |
| 0.03 – 0.05% | Mild euphoria, relaxation, talkativeness | Concentration, tracking |
| 0.06 – 0.09% | Disinhibition, reduced pain sensitivity | Reasoning, depth perception, peripheral vision |
| 0.10 – 0.19% | Boisterousness, possible nausea | Reflexes, reaction time, slurred speech, staggering |
| 0.20 – 0.29% | Nausea, vomiting, mood swings | Severe motor impairment, blackout risk |
| 0.30 – 0.39% | Stupor, lapses in consciousness | Breathing, heart rate, equilibrium |
| ≥ 0.40% | Coma, death possible | Life-threatening CNS depression |
Heavy drinking increases risks for liver disease, hypertension, cancer, and injury. Alcoholic hepatitis often shows AST disproportionately high versus ALT (ratio ≥2). Discuss screening and cessation resources with your clinician.
Never drive impaired. Estimates vary; only evidential breath or blood tests matter legally. Alcohol poisoning (confusion, slow breathing, unresponsive) is an emergency—call 911 or your local emergency number.
Help others plan safe rides and understand BAC limits
Suggested hashtags: #BAC #Alcohol #Safety #Calculator #DontDrinkAndDrive