About this tool
Roughly estimate your blood alcohol content (BAC) from your sex, weight, number of standard drinks and hours since your first drink, using the Widmark formula with a typical elimination rate. This is educational only and runs entirely in your browser.
Frequently asked questions
How accurate is this?
It is only a rough estimate. Real BAC depends on food, metabolism, medication, drink strength and more, so never use it to decide whether to drive.
What counts as one standard drink?
About 14 grams of pure alcohol — roughly a 350 ml beer, 150 ml wine or 45 ml of spirits.