≈BAC Estimate
One calculation at a time
A little more perspective

An estimate. A clear snapshot.

Enter your drinks and elapsed time. Keep the numbers behind each result.

01Your inputs

One U.S. standard drink = 12 oz beer (5%), 5 oz wine (12%), or 1.5 oz spirits (40%). Stronger or larger pours count as more.
Hours
Minutes
A rough body-water assumption, not a measurement. Individual body composition varies substantially.

02Your result

Estimated BAC
— %
Blood alcohol concentration · g/dL

Your estimate will appear here after you calculate. It stays fixed until you calculate again.

Never use this to decide whether to drive.
This is an educational estimate, not a BAC test or confirmation of sobriety. Even a result of 0.000% does not establish safety.

Saved estimates

Snapshots stay in this browser only. No timer, background updates, or ongoing logging.

How the estimate works

We use a simplified Widmark calculation: BAC (%) = max(0, (standard drinks × 14 g ÷ (body weight in grams × distribution factor)) × 100 − 0.015 × elapsed hours). The model assumes full absorption and subtracts a fixed 0.015 percentage points per hour since your first drink. Every snapshot includes these assumptions.

Actual BAC can differ considerably. Food, drink timing and strength, absorption, body composition, medications, and metabolism all affect the result. BAC may still rise after drinking stops. This model does not predict your current impairment, peak BAC, or when it will be safe to drive.

References: NIAAA · standard drinks · NHTSA · alcohol elimination · NIAAA · absorption and overdose