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BAC Calculator

Adjust the inputs below. Results update as you type.

How it works

Uses the Widmark formula: BAC = (alcohol grams) / (weight kg × r × 10) − (0.015 × hours), where r is 0.55 for women and 0.68 for men. Estimates vary by metabolism, food intake, and medication. Legal driving limits are typically 0.08% in the US but lower in many countries. Never use this to decide whether to drive—the only safe amount before driving is zero.

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