BAC Calculator

Estimate your blood alcohol content (BAC) from drinks, body weight and time using the Widmark formula. Free, instant, no signup.

How to use the BAC Calculator

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the bac calculator.
  3. Use the result. Copy the result or try a related tool next.

Why use our BAC Calculator

Instant results. Enter your figures and the bac calculator returns an answer in seconds.
Free & private. Runs in your browser — no signup, and nothing is sent to a server.
Accurate. Uses standard formulas so you can rely on the numbers.

Free to use — premium coming soon

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About the BAC Calculator

The BAC Calculator estimates your Blood Alcohol Concentration, the percentage of alcohol in your bloodstream, from the drinks you have had, your body weight, your sex, and the time elapsed since your first drink. It is built for people who want a rough sense of where they stand after a few drinks: figuring out roughly how long until you might be back near zero, understanding why the same drinks affect people differently, or simply learning how alcohol moves through the body. It gives you a number in seconds without any breathalyzer hardware or lab test.

Reach for this calculator when you are planning around alcohol rather than reacting in the moment. It is useful for estimating how long a night of drinking might keep you above a meaningful level, comparing how two people of different builds process the same drinks, or teaching responsible-drinking concepts in a class or workplace setting. A standard U.S. drink contains about 14 grams of pure alcohol, equal to a 12 oz beer at 5% ABV, 5 oz of wine at 12%, or 1.5 oz of spirits at 40%. Entering accurate drink sizes and honest timing matters far more than the math itself.

Under the hood the tool uses the Widmark formula, the method forensic toxicologists have relied on since the 1920s. In simple terms it divides the grams of alcohol you drank by your body weight times a distribution factor (r), then subtracts the alcohol your liver has already cleared. The r factor is roughly 0.68 for men and 0.55 for women, reflecting that women on average carry a smaller proportion of body water, so the same drinks spread through less fluid and produce a higher concentration. The calculator also subtracts about 0.015 BAC per hour, the average elimination rate.

Treat every result as an estimate, not a verdict. The Widmark equation assumes average body composition, average metabolism, and that alcohol is fully absorbed, yet real r values, liver speed, food in the stomach, medication, and drink strength all push the true figure up or down. The only reliable measurements come from a blood test or a properly calibrated breathalyzer used by a professional. This calculator never tells you it is safe to drive, and it runs entirely in your browser, so the drink counts and personal details you enter are processed on your device and are not sent to or stored on any server.

Frequently asked questions

What formula does this BAC calculator use?

It uses the Widmark formula, the standard forensic method since the 1920s. It divides the grams of alcohol consumed by your body weight times a distribution factor (about 0.68 for men, 0.55 for women), then subtracts roughly 0.015 BAC for each hour since your first drink to account for elimination.

Why do men and women get different BAC from the same drinks?

The difference comes from body water. Women on average have a smaller proportion of body water than men, so the Widmark distribution factor is lower (around 0.55 versus 0.68). With less fluid to dilute it, the same amount of alcohol produces a higher concentration in a woman of equal weight.

Can I trust this calculator to decide whether I can drive?

No. It is an educational estimate only and can be off by a wide margin because metabolism, food, medication, and individual body composition vary. The legal limit is 0.08% BAC in most U.S. states (0.05% in Utah), but impairment can begin below that. If you have been drinking, do not drive.

How long does it take for my BAC to return to zero?

The body eliminates alcohol at roughly 0.015 BAC per hour, and that rate cannot be sped up by coffee, water, or a cold shower. As a rough guide, a BAC of 0.08 takes more than five hours to clear. Only time lowers your BAC.

What counts as one standard drink?

In the United States a standard drink holds about 14 grams of pure alcohol. That equals a 12 oz beer at 5% ABV, a 5 oz glass of wine at 12% ABV, or a 1.5 oz shot of 40% spirits. Strong craft beers, large pours, or cocktails with multiple shots count as more than one.

From our blog

Time and a Half, Explained: How to Check Your Overtime Pay in Under a Minute

By the Super Simple Digital Tools Team · Updated June 2026

Overtime is one of the most commonly miscalculated parts of a paycheck, partly because the rules sound simpler than they are. The core idea is that hours beyond a threshold are worth more, but the threshold, the multiplier, and the definition of your pay rate all matter. Before trusting any number, it helps to separate three things: how many hours are regular, how many are overtime, and what hourly rate the premium is built on. Get those three inputs right and the rest is arithmetic the calculator handles for you.

The federal baseline is the 40-hour workweek. Once a non-exempt worker passes 40 hours in a single seven-day workweek, every additional hour must be paid at no less than 1.5 times the regular rate. A crucial detail people miss is that overtime is measured by the workweek, not the pay period. If you work 30 hours one week and 50 the next, you are owed 10 hours of overtime even though your two-week total is exactly 80. Employers cannot legally average the two weeks to avoid the premium.

Many states layer extra protection on top of the federal floor. California is the best-known example: it requires overtime after 8 hours in a single day, not just after 40 in a week, and it adds double time once you cross 12 hours in a day or work beyond 8 hours on a seventh consecutive workday. That is why a single long shift can earn overtime even in a short week. When you model these situations, switch the multiplier to 2x for the double-time portion and 1.5x for the rest, then add the results together.

The 'regular rate' is the input most likely to trip people up. Federal rules define it as more than your base wage; it can fold in nondiscretionary bonuses, shift differentials, and certain other earnings, then divide by total hours to find the true hourly figure the premium is based on. If you only worked a flat hourly job with no bonuses, your base rate is your regular rate. If your pay is more complex, treat the calculator's result as a close estimate and compare it against your pay stub line by line.

Finally, remember the number you see is gross pay. Overtime is still subject to income tax and payroll withholding, so your take-home increase is smaller than the headline figure. A temporary federal provision starting with the 2025 tax year lets eligible workers deduct a portion of qualified overtime premium pay at tax time, but that is a filing benefit, not something deducted from each check. Use the calculator to confirm you were paid correctly first, then plan around the after-tax amount.

  • Always calculate overtime per workweek, never across a two-week pay period, since the FLSA prohibits averaging two weeks to dodge the premium.
  • If you earn nondiscretionary bonuses or shift differentials, recompute your true regular rate before entering it, as your base wage alone may understate what you are owed.
  • Check your state's rules: in places like California, use the double-time (2x) option for hours past 12 in a day or beyond 8 on a seventh straight workday.
  • Compare the calculator's gross result against the overtime line on your pay stub, and if they differ, raise it with payroll with your hours and rate written down.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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