How to Use the BAC Unit Converter
Blood alcohol concentration (BAC) is expressed in different units depending on the context: BAC% is common in law enforcement and everyday use, while mg/dL and mg/100mL appear in medical and scientific contexts. This converter lets you input any of the three units and instantly see the equivalent values in the other two.
The conversion is straightforward: BAC% × 1,000 = mg/dL. Since 1 dL equals 100 mL, mg/dL and mg/100mL are numerically identical. The US federal legal limit for driving under the influence is 0.08% BAC (80 mg/dL). This tool is for educational reference only — do not use it to make decisions about driving.
Frequently Asked Questions
It means 0.08 grams of alcohol per 100 milliliters of blood, equivalent to 80 mg/dL. This is the US federal DUI threshold for non-commercial drivers.
The federal limit is 0.08% in all US states for non-commercial drivers aged 21+. Zero-tolerance laws apply to drivers under 21 (typically 0.00–0.02%).
No. This is a unit conversion tool only. Actual BAC varies greatly by body weight, sex, number of drinks, and time elapsed. Never use a calculator to decide whether to drive after drinking.