Free · no sign up · nothing stored
Most calculators give you one generic number against a flat 0.08%.
This one logs your real drinks, picks the legal limit for your state or country, and tracks your BAC live until you're clear.
● 3 calculation models ● State and country legal limits ● Live BAC curve
Method
Pick your calculation model, log what you actually drank, and set your region. Everything else updates on its own.
01
Weight, sex, and optionally height or body fat percentage, so you can choose Classic Widmark, Watson body-water, or the body fat model.
02
Add each drink with its own type, size, and time, not one lump total. Mark whether you ate, since food changes absorption speed.
03
See your live BAC, your peak, and the exact time you’ll be under your selected legal limit or fully back to zero.
Your jurisdiction
Most tools show one flat number. Select your region in the calculator and your BAC is measured against the real limit that applies to you.
Standard driver, US
0.08%
Commercial driver, US
0.04%
Under 21, US
0.00–0.02%
Utah
0.05%
UK and most of EU
0.05%
Hungary, Czechia
0.00%
Australia
0.05%
Canada
0.08%
Reference
Your live result is automatically matched to the row below, so you never have to cross-reference it yourself.
| BAC | Status | Typical effects |
|---|---|---|
| 0.00 | SOBER | No measurable impairment. |
| 0.01–0.02 | MINIMAL | Slight mood lift, barely noticeable. |
| 0.03–0.05 | MILD | Relaxation, lowered inhibitions. |
| 0.06–0.07 | IMPAIRED | Slower reaction time, judgment starts to slip. |
| 0.08–0.09 | LEGALLY IMPAIRED | Illegal to drive in most of the US. Noticeable balance and speech issues. |
| 0.10–0.15 | SEVERE | Major coordination loss, blurred vision. |
| 0.16–0.25 | DANGER | Nausea, confusion, blackout risk. |
| 0.26+ | LIFE-THREATENING | Risk of alcohol poisoning, loss of consciousness. |
While you wait
Your BAC updates automatically as time passes, with a full curve showing where you’ve been and where you’re headed.
Peak
See the highest point your BAC is projected to reach, and roughly when.
Countdown
A running countdown to when you’re under your selected region’s limit.
Curve
A live line chart of your rise and fall, with your legal limit marked directly on it.
When your estimated BAC crosses your selected legal limit, the result includes a direct next step, how long to wait, or a reminder to arrange a ride, not just a colored badge left for you to interpret.
Your results
Session summary, BAC chart, drink timeline, and the assumptions used, formatted and ready to save.
One click copies a plain-text version of your result to your clipboard.
A clean, simple snapshot of your BAC and status, easy to send in a message.
Questions
It’s a solid estimate, generally within 15 to 20% of an actual breath or blood test. Choosing the body fat percentage model and entering food intake accurately gets you closer to a realistic number.
Yes. Select your state, country, or driver type and your result is compared directly against that specific limit, rather than a generic 0.08%.
It depends on your weight, sex, and how fast you’re drinking. Log your actual drinks in the calculator for a number based on your real session rather than a rough average.
Food eaten before or during drinking can lower your peak BAC by slowing absorption, which is why our calculator has a food toggle. Coffee and water do nothing to speed up how fast your liver clears alcohol already in your blood.
Classic Widmark is the standard formula most calculators use. Watson body-water is a refinement that’s generally more accurate for most adults. Body fat percentage is the most precise, since it accounts for your actual lean-to-fat ratio.
Your session is saved locally on your own device so you don’t lose it on refresh. Nothing is sent to or stored on our servers.
No. This tool is for education and awareness. It’s not a certified device and shouldn’t be the deciding factor in whether you drive. If you’ve been drinking, the safest choice is not to.