How long until I'm sober after drinking?
Your body clears about 0.015% BAC per hour. So if your blood alcohol content is 0.060%, you're looking at roughly four hours until you hit 0.000%. That math doesn't change whether you weigh 130 pounds or 230, and it doesn't speed up with coffee, cold showers, or food. The only variable is time.
The harder question is what your BAC actually is right now. That depends on your weight, your sex, how long you've been drinking, and crucially, the alcohol-by-volume of every drink you've had. A pint of hazy IPA at 7.2% is not the same as a domestic light at 4.2%. A short pour of a barrel-aged stout at 11% is not a "standard drink" by any honest definition. Most BAC calculators round all of that into a generic "beer" preset and give you a number that's wrong by 30 to 50 percent.
Sober is a free BAC calculator built around the part everyone else hand-waves: the actual ABV of what's in your glass. Enter your weight, your sex, when you started, and each drink with its real percentage. You get a BAC estimate and a sobriety countdown. No accounts, no signup, no rehab pop-ups.
How is BAC calculated?
The math comes from Erik Widmark's 1932 formula, which is still the standard used in forensic toxicology:
BAC = (A x 5.14) / (W x r) - 0.015 x H
Where A is the total fluid ounces of pure alcohol consumed, W is body weight in pounds, r is a body water constant (0.73 for males, 0.66 for females), and H is hours since the first drink. The 5.14 converts ounces to a percentage. The 0.015 per hour is the average rate your liver metabolizes alcohol.
Sober shows you the formula, the variables it used, and the result. No black box. If you want to check the number against a different calculator, every input is right there. The Widmark formula has known soft spots: food in your stomach, individual liver variation, body composition. The disclaimer says so. It's an estimate, not a breathalyzer.
Why does craft beer mess up other BAC calculators?
Because every other major calculator was built around the "standard drink" concept from the 1980s, when a beer was essentially always 4 to 5 percent. The standard-drink model assumes 0.6 fluid ounces of pure alcohol per "drink" and presents a counter that says "how many beers, how many wines, how many shots." Tap that "+1 beer" button three times and the calculator thinks you had 1.8 ounces of alcohol.
Three modern craft beers can easily be 3.6 ounces of alcohol. That's twice the math.
Walk into a halfway-decent bar in 2026 and the draft list is double IPAs at 8 to 9%, imperial stouts north of 10%, hazy pales sitting at 6.5%, plus whatever barrel-aged thing is on at 12%. Wine's the same story. A Napa cab is often 14.5 or 15%, not the textbook 12%. And cocktails depend entirely on whether the bartender is using a 1.5-ounce jigger or free-pouring something closer to 2.5.
Sober's drink entry has a default ABV for each category, but every default is editable. Punch in your craft IPA at 7.2, your house red at 14.5, your old fashioned with 2.5 ounces of bourbon. The calculator handles the conversion to fluid ounces of pure alcohol. The math is the same Widmark math everyone else uses. The inputs are just honest about what you actually drank.
How does body weight affect BAC?
Body weight matters because alcohol distributes through your body water. Heavier people generally have more body water, so the same amount of alcohol gets diluted across a larger volume and produces a lower BAC. The Widmark formula divides by weight directly, which is why a 220-pound person and a 130-pound person who drink the same two beers will not land on the same number.
Sex factors in for the same reason. The "r" constant in Widmark accounts for males having, on average, a higher percentage of body water than females. Sober labels it as biological sex because that's what the formula needs. No implication, no judgment, just a variable.
What the formula doesn't capture well is body composition. A very lean 180-pound athlete and a 180-pound person with higher body fat will land on slightly different actual BACs from the same drinks, because muscle holds more water than fat. Widmark treats them identically. That's a real limitation. In practice the gap is small enough that the bigger source of error is almost always the ABV input, which is the part Sober actually lets you fix.
What is the legal BAC limit to drive in the US?
In every US state except Utah, the per se legal limit for drivers 21 and over is 0.08% BAC. In Utah it's 0.05%. Commercial drivers are held to 0.04% nationwide, and drivers under 21 are subject to zero-tolerance laws (typically 0.01 or 0.02%) in every state.
Sober displays a clear legal-limit indicator with every result. Below 0.04% reads green. Between 0.04% and 0.079% reads yellow. At or above 0.08% reads red. There's no "you are fine to drive" message at any level, because no one should be making that call from a calculator. What the indicator does is answer the only question worth asking: am I above or below the legal threshold right now, and how long until I'm not.
The sobriety countdown is the second half of that answer. If your BAC is 0.061%, you're below 0.08%, but you're not at zero. The timer tells you it's about four hours and four minutes until you hit 0.000%. That's planning information. That's the difference between "I'll be fine in an hour" and "I'm calling a Lyft."
Can a BAC calculator replace a breathalyzer?
No. Any calculator that suggests otherwise is lying. A breathalyzer measures alcohol vapor in your actual breath. A BAC calculator does pencil-and-paper math from estimates. Sober says so on the result screen every time, in plain language. The number is useful. It's not a permission slip.
What a calculator is good for is the planning side. Before you start, you can model what two beers over two hours looks like for your body. Mid-evening, punch in what you've actually had and see whether the next one is worth it. The morning after, check when you're likely to be clear so you know whether you can drive yourself to brunch.
Try Sober
Sober was built for the moment you want a real answer in under thirty seconds, on your phone, in a bar, without scrolling past three rehab ads to get there. Enter your weight. Pick male or female. Type how many hours since your first drink. Add each drink with its actual ABV. Tap calculate. You get your BAC, your time until clear, and an above-or-below-legal indicator. That's the whole tool.
Free, mobile, no account. Open Sober the next time you need to know.