BAC Calculator
Estimate your Blood Alcohol Content — for educational use only
⚠️ This calculator provides estimates only. Individual BAC varies based on many factors. Never drink and drive. Call a rideshare, designated driver, or taxi if you have been drinking.
BAC Levels & Effects Chart
| BAC % | Effects | Legal Status |
|---|---|---|
| 0.01–0.03% | Mild warmth, subtle relaxation. Mostly unnoticeable. | Legal |
| 0.04–0.06% | Relaxed, lowered inhibitions, mild euphoria, slight impairment of judgment. | Legal |
| 0.07–0.08% | Reaction time slowed, coordination slightly off, judgment impaired. At the legal limit. | ⚠️ At limit |
| 0.09–0.12% | Clear coordination impairment, balance affected, reaction time significantly slowed. | 🚫 Over limit |
| 0.13–0.15% | Severe impairment, gross motor function loss, blurred vision, nausea possible. | 🚫 Over limit |
| 0.16–0.19% | Nausea, vomiting, disorientation, loss of balance. Driving extremely dangerous. | 🚫 DUI risk |
| 0.20–0.25% | Confusion, needs assistance standing/walking, vomiting, possible blackout. | 🚫 Danger |
| 0.25–0.30% | Stupor, minimal response to stimuli, loss of consciousness possible. | ☠️ Emergency |
| 0.30%+ | Loss of consciousness, risk of alcohol poisoning, potentially fatal. Call 911. | ☠️ Call 911 |
What Is a Standard Drink?
| Drink | Amount | ABV | Pure Alcohol |
|---|---|---|---|
| 🍺 Regular beer | 12 oz (355 ml) | 5% | 14 g (0.6 oz) |
| 🍺 Light beer | 12 oz (355 ml) | 4.2% | 11.8 g |
| 🍺 IPA / Craft beer | 12 oz (355 ml) | 6–9% | 17–30 g |
| 🍷 Table wine | 5 oz (148 ml) | 12% | 14 g (0.6 oz) |
| 🍷 Fortified wine | 3.5 oz (104 ml) | 17% | 14 g |
| 🥃 80-proof spirits | 1.5 oz (44 ml) | 40% | 14 g (0.6 oz) |
| 🥃 100-proof spirits | 1.5 oz (44 ml) | 50% | 17.5 g |
| 🍹 Hard seltzer | 12 oz (355 ml) | 5% | 14 g |
Cocktails count as multiple standard drinks. A Long Island Iced Tea can contain 4–5 standard drinks. A large glass of wine (9 oz at 15% ABV) is nearly 2 standard drinks. Always check the actual size and ABV.
Time to Sober Up Reference
Approximate hours until BAC reaches 0.00%. Liver metabolizes ~0.015% BAC per hour.
| Peak BAC | Hours to reach 0.08% | Hours to reach 0.00% |
|---|---|---|
| 0.04% | Already under | 2.7 hours |
| 0.08% | Already at limit | 5.3 hours |
| 0.10% | 1.3 hours | 6.7 hours |
| 0.12% | 2.7 hours | 8.0 hours |
| 0.15% | 4.7 hours | 10.0 hours |
| 0.20% | 8.0 hours | 13.3 hours |
Coffee, food, and cold showers do NOT lower BAC. They may make you feel more alert, but your BAC remains the same. Only time reduces blood alcohol. If your BAC is over 0.08%, you must wait — there are no shortcuts.
Factors That Affect BAC
| Factor | Effect on BAC |
|---|---|
| Body weight | Heavier = lower BAC (more body water to dilute alcohol) |
| Biological sex | Women have higher BAC from same amount (lower body water %) |
| Food intake | Full stomach slows absorption, lowers peak BAC |
| Drinking pace | Faster drinking = higher peak BAC |
| Carbonated mixers | Speed up absorption (champagne, soda mixers) |
| Age | Older adults process alcohol more slowly |
| Medications | Many drugs intensify alcohol effects at same BAC |
| Hydration | Dehydration increases perceived effects |
Frequently Asked Questions
What BAC is legally drunk in the US?
0.08% in all 50 US states for drivers 21 and over. Commercial drivers: 0.04%. Drivers under 21: 0.00–0.02% (zero tolerance in most states). Utah has a lower limit of 0.05% for all drivers.
How long does alcohol stay in your system?
Blood alcohol metabolizes at ~0.015% per hour. A typical night of 3–4 drinks (peak BAC ~0.08–0.10%) takes 5–7 hours to fully clear. Urine tests can detect alcohol for 12–48 hours. Breathalyzers typically detect alcohol within the past 24 hours.
Does BAC of 0.08% mean I'm visibly drunk?
Not always. Regular drinkers develop tolerance and may not appear impaired at 0.08%. However, reaction time, visual tracking, and judgment are measurably impaired at this level regardless of how you feel. Tolerance does not reduce driving impairment.
How accurate is this BAC calculator?
This calculator uses the Widmark formula, the most widely used BAC estimation method. However, individual BAC can vary by ±30–50% due to genetics, food intake, medications, and health status. Treat results as estimates only — never rely on a calculator to decide whether to drive.
What should I do if someone's BAC is dangerously high?
A BAC over 0.25% is a medical emergency. Signs of alcohol poisoning: unconsciousness, slow/irregular breathing, blue-tinged skin, vomiting while unconscious. Call 911 immediately. Put them in the recovery position (on their side). Do not leave them alone.