Blood Alcohol Concentration (BAC) Calculator

Icon of a clock with what appears to be a beer bottle and a beer glass in front of a red circle

Curious about BAC?

This BAC calculator is an estimate only for demonstration purposes.
Everyone metabolizes alcohol differently and this BAC calculator should NOT be used to determine someone’s intoxication level or if they are okay to drive.

Disclaimer and Release

“I understand that although a person’s Blood Alcohol Concentration (BAC) level can be estimated, this BAC calculator (tool) is for demonstration and educational purposes only.

The exact level cannot be determined solely by the amount of alcohol consumed and body weight. There are numerous individual factors that are influenced by a persons metabolism, health, medications, food eaten, etc. This BAC calculator assumes an elimination rate of alcohol from the body of 0.015 mg/100 mL/hour. Rates may vary between 0.01 and 0.025 mg per 100 mL/hr.

This tool should NOT be used as the sole way to determine someone’s intoxication level or if they can legally drive.

I understand that this tool is being provided to me on an “”as is”” basis and that I am using it entirely at my own risk. I further understand that Smart Serve Ontario (SS0) is disclaiming all representations, warranties, conditions, guarantees or conditions of any kind, either express or implied, regarding the completeness, accuracy, reliability, usefulness, availability, or appropriateness of the tool, including any results that may be obtained from my use. I acknowledge that the results may include technical data inaccuracies and that SSO, its directors, officers or employees, will not be liable to me for any damages of any kind arising from my use of the tool.

BAC calculations prepared by Homewood Research Institute, James MacKillop, PHD (Senior Scientist, Peter Boris Centre for Addiction Research) and Jean Costello, PHD ( Director of Evaluation). Report funded by and prepared for Smart Serve Ontario.”

Yes, I understand
Details

Use this tool to calculate BAC over a period of time, based on how much alcohol is consumed.

Sex
# of Drinks
Drinks
Weight
lbs
Time
Hours
Estimate BAC
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After standard drinks consumed in hours, your BAC level will be approximately %.

What is a Standard Drink

A standard drink is based on the volume of the drink and its alcohol content (% ABV). Your body takes 1 hour to process one standard drink, but this should be used as a guide only. There are many factors that will affect this time.

standard drink

BEER/CIDER = 12 oz (341 mL) of beer or cider with 5% alcohol

standard drink

WINE= 5 oz (142 mL) of wine with 12% alcohol

standard drink

SPIRITS = 1.5 oz (43 mL) of spirits with 40% alcohol

TIME
ESTIMATE BAC %
1 hour
result medium result fail result-pass
2 hours
result medium result fail result-pass
3 hours
result medium result fail result-pass
4 hours
result medium result fail result-pass
5 hours
result medium result fail result-pass
6 hours
result medium result fail result-pass
7 hours
result medium result fail result-pass
8 hours
result medium result fail result-pass
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Tips
Instructions

Enter individual details by toggling on the 4 key variables: Sex, Weight, Number of Standard Drinks, and the Time they were consumed in.

IMPORTANT: This BAC Calculator uses a formula to estimate the BAC level, but does not take into account numerous other factors that may influence an individual’s situation (for example: age, health, food eaten, medications, etc.).

Understanding BAC

Blood Alcohol Concentration (BAC) is the amount of alcohol in the bloodstream. How much alcohol & how quickly it is being consumed are 2 key factors that affect a persons BAC level.

The more standard drinks consumed, in a shorter period of time, the higher the BAC level. BAC will continue to rise, even after the last drink is consumed. Alcohol is metabolized typically at a rate of 1 standard drink per hour.

What is One Standard Drink?

Each of these drinks contain exactly the same amount of alcohol (0.6 ounces / 17 mL of pure alcohol) & will have the same effect on the body.

BEER/CIDER = 12 oz (341 mL) of beer or cider with 5% alcohol
WINE= 5 oz (142 mL) of wine with 12% alcohol
SPIRITS = 1.5 oz (43 mL) of spirits with 40% alcohol

This BAC Calculator (tool) uses the calculation that each drink entered is equal to 1 standard drink & assumes an elimination rate of 1 standard drink per hour. Under most social drinking conditions, drinks are consumed every 20-minutes. Patterns will change with extended periods of drinking.

IMPORTANT: This BAC Calculator (tool) is only a general guideline to give you an estimated BAC level.

Additional Factors

How fast a person’s BAC rises depends on a number of additional factors including: age, body size, body fat, fitness level, type and amount of food eaten, drugs or other medications taken.

NOTE: Age is not a factor when determining the BAC level calculation for females. This BAC Calculator (tool) assumes male calculations are based on a 25-year-old in good health.

Colour Legend

RED indicates a BAC level of 0.08 or more
YELLOW indicates a BAC level between 0.05 to 0.079
GREEN indicates a BAC level 0.00 to 0.049

If you are 21 years of age or under or have a G1, G2, M1 or M2 licence you cannot have any alcohol in your system. You will face penalties, plus you can face additional penalties for impairment just like any other fully licenced-driver.

Driving in Ontario with a BAC level of 0.05-0.079 is what is known as the warn range and there are penalties and may result in an immediate driver’s licence suspension under the Highway Traffic Act. Throughout Canada, driving with a BAC level of 0.08 or more is a criminal offence.

IMPORTANT: This BAC Calculator (tool) is only a general guideline & can only give you an estimated BAC level. It should NOT be used to determine intoxication or if you are okay to drive.