BAC Calculator (Blood Alcohol Content)
Overview
Calculate your blood alcohol content using the Widmark formula. Estimate BAC based on drinks, weight, sex, and time elapsed. Never drink and drive.
Key Facts
| Field | Value |
|---|---|
| Calculator ID | bac |
| Category | Health |
| Vertical | Health & Fitness |
| App route | /verticals/health/bac |
| API endpoint | /api/public/calculate?id=bac |
Inputs
| Input ID | Label | Type | Required | Default | Constraints |
|---|---|---|---|---|---|
sex | Sex | select | Yes | male | - |
weight | Body Weight (lbs) | number | Yes | 180 | min 50, max 500, step 1 |
drinks | Number of Drinks | number | Yes | 3 | min 0, max 20, step 0.5 |
hours | Hours Since First Drink | number | Yes | 2 | min 0, max 24, step 0.25 |
emptyStomach | Drinking on Empty Stomach? | select | Yes | no | - |
How to Use
- Enter Personal Info — Input your biological sex and body weight in pounds. These affect alcohol metabolism rates.
- Count Your Drinks — Enter number of standard drinks consumed (12oz beer, 5oz wine, or 1.5oz spirits = 1 drink).
- Time Since First Drink — Enter hours elapsed since your first drink, not your last. Body metabolizes alcohol at ~0.015% BAC per hour.
Result Surfaces
| Output | Display Type | Format |
|---|---|---|
| Computed results | result-card | - |
Related Calculators
FAQ
What BAC is considered legally drunk?
0.08% BAC is the legal limit for driving in all 50 states. However, impairment begins at 0.02-0.03% with reduced reaction time and judgment. Commercial drivers have 0.04% limit. Zero tolerance for drivers under 21 (any BAC over 0.00% is illegal). DUI penalties: $10,000+ in fines, license suspension, jail time.
How long does it take to sober up?
Body metabolizes alcohol at ~0.015% BAC per hour (1 standard drink per hour). Nothing speeds this up - not coffee, cold showers, or food. Example: 0.08% BAC takes 5-6 hours to reach zero. Plan ahead: designated driver, rideshare ($20 Uber vs $10,000 DUI).
How accurate are BAC calculators?
BAC calculators provide estimates only. Actual BAC varies by metabolism, medications, health conditions, food in stomach, and individual factors. Only a breathalyzer or blood test gives accurate BAC. Use calculators for planning, not to determine if you can drive. When in doubt, don't drive.
Evidence
src/lib/calculators/registry.ts(metadata)src/lib/calculators/page-registry.ts(page/HowTo metadata)src/lib/calculators/health/bac.ts(calculator config)