BAC Calculator
Estimate your blood alcohol content (BAC) with the Widmark formula from your weight, sex, standard drinks and time. For education only — never use it to decide whether to drive.
Standard-drink definitions vary by country.
About this BAC estimate
This Widmark estimate uses ranges for body-water distribution and alcohol metabolism instead of presenting a single precise number. It is not a sobriety test and cannot tell you when it is safe to drive.
FAQ
How is BAC estimated?
This tool uses Widmark ranges rather than a single point estimate. It calculates both ends using r = 0.60–0.73 for males or 0.49–0.61 for females and metabolism = 0.012–0.020 BAC percentage points per hour.
Is this accurate enough to decide if I can drive?
No. Never drive after drinking. This educational estimate can differ greatly from your actual BAC and cannot tell you whether or when it is safe to drive.
What is a standard drink?
Definitions vary by country. Choose either 10 g or 14 g of pure alcohol per standard drink, or enter beverage volume and ABV instead.
How does the beverage input work?
Enter the beverage volume in ml or US fl oz and its ABV. The calculator converts that to grams of pure alcohol using an ethanol density of about 0.789 g/ml.
Is my information stored or shared?
No. The calculation runs locally in your browser. Your entries are not uploaded, stored or shared.
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