Blood Alcohol Content (BAC) Calculator — Canada

The legal limit for impaired driving in Canada is 0.08% BAC (80 mg of alcohol per 100 mL of blood) under section 253 of the Criminal Code. However, drivers found between 0.05% and 0.079% face provincial 'warn range' consequences including roadside suspensions and fines without a criminal charge. Drivers under 25 or with an N/L licence face a zero-tolerance standard.

Yes. Police can charge you with impaired driving regardless of BAC if they observe signs of impairment — slurred speech, poor coordination, or erratic driving. A BAC under 0.08% does not immunize you from a criminal impaired driving charge under s. 253(1)(a) of the Criminal Code.

BAC is a concentration — the amount of alcohol in your blood. A heavier person has more blood volume, diluting the same amount of alcohol further. A 90 kg person will reach a lower BAC from the same drinks than a 60 kg person. However, tolerance is not the same as BAC — chronic drinkers may show fewer signs of impairment at higher BAC levels.

The liver metabolizes alcohol at approximately 0.015% BAC per hour on average. There is no way to accelerate this — coffee, water, food, and sleep do not speed metabolism. If your BAC is 0.12%, you will require approximately 2.7 hours to reach 0.05% and 5.3 hours to reach zero.