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Blood Alcohol

Detailed blood alcohol content estimator. Enter values for instant results with step-by-step formulas.

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Health & Fitness

Blood Alcohol Calculator

Estimate your Blood Alcohol Concentration (BAC) based on drinks, weight, and time. For educational purposes only.

Last updated: January 2026Reviewed by NovaCalculator Medical Editorial Team

Calculator

Adjust values & calculate

🍺 Estimated BAC

0.046%

⚠️ DISCLAIMER: This is an estimate only. Never drink and drive. Individual response to alcohol varies significantly. When in doubt, don't drive.

2 hrs
Estimated BAC
0.046%
Slight relaxation, mild mood change
Drinks
3.0
Peak
0.076%
Sober
3.0h
Your Result
BAC: 0.046% - LOW
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Understand the Math

Formula

BAC = (Alcohol grams / (Weight × r)) - (Hours × 0.015)

This Blood Alcohol Calculator computes results from your provided inputs using the calculator's underlying model.

Last reviewed: January 2026

How to Use This Calculator

  1. Select your gender and weight.
  2. Choose your drink type (Beer, Wine, Shot, etc.) and quantity.
  3. Set the time elapsed since your first drink.
  4. View your estimated BAC and when you might be sober.

Worked Examples

Example 1: After Dinner

180 lb male, 3 beers over 2 hours.
Solution:
Alcohol: 3 × 14g = 42g Peak BAC: ~0.063% After 2 hrs: 0.063 - 0.030 = 0.033%
Result: BAC: ~0.033% (below legal limit)
Expert Insights

Key Features

  • Estimates Blood Alcohol Concentration (BAC)
  • Uses Widmark Formula
  • Time to Sober estimation
  • Visual Impairment Gauge
  • Adjusts for Gender, Weight, and Drink Type
  • Warning indicators for driving limits
Explore More

Frequently Asked Questions

Body metabolizes ~0.015% BAC per hour (about 1 standard drink). A BAC of 0.08% takes ~5.3 hours to reach zero. Only time reduces BAC - coffee, food, etc. don't help.
Educational Note: This calculator is provided for educational and informational purposes. Results are based on the formulas and inputs provided. Always verify important calculations independently. NovaCalculator processes calculator inputs client-side; optional analytics follow visitor consent settings.Reviewed by: NovaCalculator Medical Editorial Team — Reviewed against WHO, NIH, and peer-reviewed clinical sources. Last reviewed: January 2026. © 2024–2026 NovaCalculator.

Formula

BAC = (Alcohol grams / (Weight × r)) - (Hours × 0.015)

This Blood Alcohol Calculator computes results from your provided inputs using the calculator's underlying model.

Worked Examples

Example 1: After Dinner

Problem:180 lb male, 3 beers over 2 hours.

Solution:Alcohol: 3 × 14g = 42g\nPeak BAC: ~0.063%\nAfter 2 hrs: 0.063 - 0.030 = 0.033%

Result:BAC: ~0.033% (below legal limit)

Frequently Asked Questions

How long does alcohol stay in your system?

Body metabolizes ~0.015% BAC per hour (about 1 standard drink). A BAC of 0.08% takes ~5.3 hours to reach zero. Only time reduces BAC - coffee, food, etc. don't help.