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BAC Calculator
Estimate your blood alcohol content with the Widmark formula using your weight, gender, number of drinks, drink type, and time since your first drink.
Estimated BAC
1.065
Impairment Level
Dangerous
Estimated Time Until Sober
71.0 hours
Driving Status
Over the legal driving limit
This is an estimate only. Do not drink and drive. BAC varies by individual.
Based on 2 drinks, about 28.0 g of alcohol, 180 lbs body weight, and 2.00 hours elapsed.
EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.
Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.
Learn more about our review process on the EveryCalc methodology page.
How this calculator works
What this page estimates
This BAC Calculator is built to give a quick, browser-based estimate for bac. Estimate your blood alcohol content with the Widmark formula using your weight, gender, number of drinks, drink type, and time since your first drink. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.
Calculation approach
The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For health tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.
Example workflow
For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.
Practical checks
- Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
- Run a low, base, and high case when the inputs are estimates.
- Check the related calculators below when the next decision depends on a different assumption.
How to interpret the bac result
Best use
Use the result as an informational wellness estimate that can help organize measurements, targets, or timing before a conversation with a clinician.
Cross-check
Compare the output with your own records, device readings, lab values, medication instructions, or guidance from a qualified health professional.
Watch for
Do not use this page to diagnose, treat, or ignore symptoms. Health calculators are most useful when they make questions clearer, not when they replace care.
This page belongs to the Health calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.
Before relying on this bac estimate
Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.
Use current measurements
Recent weight, height, age, activity, nutrition, sleep, or timing inputs matter more than remembered estimates.
Look for context
A calculator can organize a wellness number, but it cannot read symptoms, medical history, medications, or lab results.
Escalate high-impact questions
Use clinical guidance for pregnancy, dosage, heart, risk, illness, or treatment decisions.
Rerun this page when measurements change, a clinician gives new guidance, or the result is being used for a new goal.
How to Use
- Choose your gender and enter your body weight in pounds or kilograms.
- Select a drink type, then enter how many drinks you had. For cocktails, customize the size and alcohol percentage.
- Enter the number of hours since your first drink.
- Review your estimated BAC, impairment level, time until sober, and whether you are over the common 0.08 driving threshold.
Frequently Asked Questions
How is BAC estimated?
This calculator uses the Widmark formula, which estimates BAC from the amount of alcohol consumed, your body weight, sex-based distribution ratio, and time for alcohol elimination. It is only an approximation.
Is one drink always the same?
No. Drink sizes and alcohol percentages vary. A standard U.S. drink contains about 14 grams of pure alcohol, which is roughly equal to a 12-ounce beer at 5%, 5 ounces of wine at 12%, or a 1.5-ounce shot at 40%.
Can I drive if my BAC is below 0.08?
Not necessarily. Many people are impaired well before 0.08 BAC, and some places use stricter legal thresholds. The safest choice is not to drive after drinking.
Why is this only an estimate?
Actual BAC depends on food intake, medications, metabolism, hydration, drinking pace, health conditions, and individual biology. Breath or blood testing is the only way to measure BAC more directly.
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