Blood Alcohol Calculator (BAC estimate)

Estimate your blood alcohol level (g/L) using the Widmark formula.

Result

Estimated BAC (g/L)

0.42

How it works

BAC = alcohol(g) ÷ (r × weight) − 0.15 × hours

A Widmark estimate only. It varies with food, metabolism and more. A standard drink ≈ 10 g of pure alcohol. NEVER use this to decide whether to drive — if you have drunk, do not drive.

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Frequently asked questions

How much is one standard drink?

About 10 g of pure alcohol (a small beer, a glass of wine or a shot).

Can I rely on this to drive?

No. It is an estimate only; the only safe level for driving is zero. Never drive after drinking.

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