RediCalc.com
Last updated: June 1, 2026

Blood Alcohol Content Calculator

Estimate your blood alcohol content based on the number of drinks, your body weight, gender, and time elapsed. This is for educational purposes only.

Disclaimer: This calculator provides estimates only. Never drink and drive. BAC is affected by many factors not captured here. When in doubt, do not drive.

Drinking Details

BAC Estimate

Estimated BAC0.0404%
StatusMildly Impaired
Est. Time to Sober2.7 hours
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Understanding the BAC Calculator

A blood alcohol content (BAC) calculator estimates the concentration of alcohol in your bloodstream based on the drinks consumed, your body weight, sex, and the time elapsed. It is an educational tool to help you understand how alcohol affects you — never a green light to drive.

What affects your BAC

BAC rises with the number and strength of drinks and falls slowly as your liver metabolizes alcohol — at a roughly fixed rate that nothing speeds up. Body weight, sex, food in your stomach, and individual metabolism all influence the result, which is why the same drinks affect two people very differently.

Why estimates can never justify driving

This calculator gives an approximation, not a legally or medically precise reading. Real BAC depends on factors no formula can capture perfectly. In most places the legal driving limit is 0.08%, but impairment begins well below that. If you have been drinking at all, the only safe choice is not to drive.

Tips & things to know

  • Only time lowers BAC — coffee and water do not speed it up.
  • Impairment starts well below the legal limit.
  • Never use an estimate to decide it is safe to drive.

How BAC Is Estimated

Uses the Widmark formula to estimate BAC based on alcohol consumed, body weight, and metabolization time.

BAC = (Drinks × 0.6 × 5.14) / (Weight × r) - 0.015 × Hours

Sources

  • NHTSA. "Alcohol-Impaired Driving."

How to Use the BAC Calculator

1

Open the BAC Calculator

Navigate to the BAC Calculator page on Redicalc. The calculator loads instantly with no sign-up required.

2

Enter your values

Fill in body measurements such as age, weight, height, and gender. Toggle between metric and imperial units if available.

3

Review your results

Your bac results appear instantly as you type. Review the breakdown, charts, or detailed analysis provided.

4

Adjust and compare

Try different input values to compare scenarios. This helps you understand how changes affect the outcome.

5

Share or save your results

Use the copy or share buttons to save your results. You can also bookmark the page for quick access later.

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Frequently Asked Questions

What BAC is legally drunk?

In all US states, a BAC of 0.08% or higher is legally impaired for drivers 21+. Commercial drivers: 0.04%. Under 21: typically 0.00-0.02%.

How long does it take to sober up?

Your body metabolizes alcohol at about 0.015% BAC per hour. Nothing speeds this up — not coffee, food, or cold showers.