BAC Calculator

Free blood alcohol content (BAC) calculator using the Widmark formula. Enter your weight, gender, number of drinks, and time elapsed to estimate your BAC level. See impairment levels, legal limits, and estimated time until sober. Important: this is an estimate only.

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Important Disclaimer

This calculator provides estimates only. Actual BAC varies based on metabolism, food intake, medications, tolerance, and other individual factors. This tool is for educational purposes only. Never drink and drive.

Gender

Widmark factor: 0.68 (affects alcohol distribution)

Body Weight

Type of Drink

Number of Drinks

Drinking Duration (hours)

How long you spent drinking

Hours Since Last Drink

Time elapsed after your last drink

Estimated BAC

0.000%

Sober

Little to no impairment. Normal behavior and mood.

Total Alcohol

42.0g

Pure alcohol consumed

Time Until Sober

0h 0m

Until BAC reaches 0.000

US Legal Status

Under Limit

Below 0.08 US legal limit

BAC Scale

0.00

0.02

0.04

0.08

0.15

0.30+

BAC Impairment Levels

Sober0.000 - 0.020You are here

Little to no impairment. Normal behavior and mood.

Mildly Affected0.020 - 0.040

Slight euphoria, relaxation. Minor impairment of reasoning and memory.

Impaired0.040 - 0.080

Reduced coordination, impaired judgment, lowered alertness. Driving ability is significantly affected.

Legally Drunk (US)0.080 - 0.150

Poor muscle coordination, impaired self-control, reasoning, and memory. Illegal to drive in most US states.

Severely Impaired0.150 - 0.300

Major loss of balance, vomiting likely, significant mental impairment. Risk of blackout.

Life-Threatening0.300 - ...

Loss of consciousness possible, risk of alcohol poisoning, potential for death. Seek emergency medical attention.

Legal BAC Limits by Country

Country	Legal Limit	Your Status
United States	0.08%	Under Limit
United Kingdom	0.08%	Under Limit
Canada	0.08%	Under Limit
Australia	0.05%	Under Limit
Germany	0.05%	Under Limit
France	0.05%	Under Limit
Japan	0.03%	Under Limit
Sweden	0.02%	Under Limit
Norway	0.02%	Under Limit
Poland	0.02%	Under Limit

How This Was Calculated

Widmark Formula:

BAC = (Alcohol in grams / (Body weight in grams x r)) - (0.015 x hours)

Alcohol consumed: 3 x 12oz x 5% ABV = 42.0g

Widmark r factor (male): 0.68

Raw BAC (before metabolism): 0.001%

Metabolized (2.0h x 0.015): 0.030%

Estimated BAC: 0.000%

This is an estimate only based on the Widmark formula. Many factors affect actual BAC including food intake, body composition, hydration, medications, and individual metabolism. When in doubt, do not drive. If you or someone you know may have alcohol poisoning, call emergency services immediately.

How to Use BAC Calculator

1Select your gender and enter your body weight.
2Enter the number and type of drinks consumed.
3Enter hours spent drinking and hours since last drink.
4View your estimated BAC, impairment level, and time to sober.

Frequently Asked Questions

How is BAC calculated?▾

Using the Widmark formula: BAC = (Alcohol in grams / (Body weight × distribution ratio)) - (0.015 × hours). The distribution ratio is 0.68 for men and 0.55 for women.

What is the legal BAC limit?▾

In the US, the legal limit is 0.08% for drivers 21+. Many countries have lower limits (0.05% in Australia, 0.03% in Japan). Commercial drivers in the US have a 0.04% limit.

How long until I am sober?▾

Your body eliminates alcohol at approximately 0.015% BAC per hour. So from 0.08% BAC, it takes about 5.3 hours to reach 0.00%.

About BAC Calculator

NexTool's BAC Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.