Estimate BAC with clearly stated population distribution and elimination assumptions. Never use a BAC estimate to decide whether to drive.
01 / YOUR INPUTS
Use the volume and ABV of the actual servings—not a country-specific “standard drink”. The first entry is an editable example: one 330 mL serving at 5% ABV.
02 / EDUCATIONAL ESTIMATE
Complete the inputs to explore an educational model estimate.
03 / METHOD & LIMITATIONS
Alcohol grams = Σ(servings × volume in mL × ABV/100 × 0.78945 g/mL). Ethanol density is taken at 20°C. One US fl oz = 29.5735295625 mL; one lb = 0.45359237 kg. US and Imperial fluid ounces are different.
Distribution volume Vd = weight in kg × the selected 0.71 or 0.58 L/kg factor. BAC (%) = max(0, alcohol grams ÷ (10 × Vd in liters) − elimination rate in g/dL/hour × elapsed hours). Dividing g/L by 10 gives g/dL, the percentage convention used here.
The model assumes all reported alcohol is absorbed as one aggregate dose and linear elimination begins at the start of the entered period. It does not model absorption delays or the timing of separate beverages. Absorption, food, medications, individual physiology and drinking patterns can substantially change actual BAC. In particular, it can underestimate BAC during continued drinking and is unreliable near the model floor.
The distribution factors are population approximations, not individual medical reference values. The editable 0.015 g/dL/hour default and 0.010–0.035 range follow Jones's published elimination review. Neither the default nor a selected higher rate measures your personal elimination rate.
Software input bounds: weight 20–500 kg, elapsed time 0–72 hours, up to 100 servings per entry, 5,000 mL per serving, 10 entries and 1,000 g total ethanol. These are implementation limits, not medical thresholds. No driving eligibility, legal-limit comparison or time-to-drive prediction is produced.
Published Widmark model summary and distribution references · Maskell et al. (2023), distribution volumes · Jones (2010), elimination-rate review · Ethanol density reference
Values are processed locally in browser memory without uploads or storage.
Enter your values locally; no inputs are uploaded.
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Review the explanation, copy supported outputs or reset the workspace.
Enter weight, the distribution parameter, serving count, beverage volume, ABV and elapsed hours. Advanced options allow additional beverages and an editable elimination assumption. Review the limitations before copying the estimate.
Documented model, metric and US volume units, multiple beverages and clear educational limitations without driving-time predictions.
Your measurements and beverage entries are calculated locally without uploads or storage.
A volume-of-distribution form of the Widmark model: estimated BAC in g/dL (%) = max(0, alcohol grams / (10 × body weight in kg × distribution factor in L/kg) − elimination rate × elapsed hours). It assumes instantaneous absorption and constant elimination, not a complete physiological simulation.
The selected population-average distribution approximations are 0.71 L/kg for a male-derived parameter and 0.58 L/kg for a female-derived parameter, as summarized in published Widmark-model references. They are not an individual's measured body-water fraction or a gender-identity assessment.
Grams = number of servings × volume in mL × ABV/100 × 0.78945 g/mL, using ethanol density at 20°C. One US fluid ounce is exactly 29.5735295625 mL and one pound is 0.45359237 kg. Servings are not country-specific standard drinks.
The editable default is 0.015 g/dL per hour. The supported 0.010–0.035 range follows the physiological range summarized by Jones (2010), DOI 10.1016/j.forsciint.2010.02.021. This is an assumption, not a measurement of your metabolism, and higher values do not establish that alcohol has cleared.
No. Zero is only the model's nonnegative floor, not evidence that alcohol has cleared or that any activity is appropriate. Absorption can continue after drinking. Never use a BAC estimate to decide whether to drive.
Actual BAC depends on absorption, food, medications, individual physiology and the timing of each drink. This aggregate model can overestimate or underestimate actual BAC, especially during absorption or continued drinking. It is not a breathalyzer or medical test and provides no driving eligibility, legal-limit comparison or time-to-drive recommendation.