Blood Alcohol Content (BAC) Calculator

Estimate blood alcohol concentration (educational only).

Standard drinks

Body weight

Sex

Hours since first drink

Estimated BAC (%) 0.0582

Formula: Widmark: BAC = alcohol(g) ÷ (weight·r) − 0.015·hours

Step-by-step with your numbers:

1. Values used:

2. Standard drinks = 3

3. Body weight = 70

4. Hours since first drink = 2

6. Estimated BAC = 0.0582%

Did we solve your problem today?

A rough Widmark estimate of blood alcohol — for education only, NOT for deciding whether to drive. Never drive after drinking.

The math behind it

BAC ≈ alcohol grams ÷ (body weight in g × r) × 100 − 0.015 × hours. r ≈ 0.68 (men), 0.55 (women); a standard drink ≈ 14 g alcohol.

3 drinks, 70 kg male, 2 h → ~0.058%.

Is this legal proof?

No — it's a rough estimate. Many factors affect real BAC; never use it to judge fitness to drive.