What Is the Legal Limit for Alcohol Consumption in Massachusetts?

In Massachusetts, it is illegal to operate a motor vehicle with a Blood Alcohol Content (BAC) of .08% or greater. For individuals under the age of 21, the Massachusetts RMV will suspend your license for operating a motor vehicle with a .02% BAC or higher. Operators of a commercial driver’s license (CDL) face a CDL suspension for operating a motor vehicle with a BAC of at least .04%.”

How to Calculate Blood Alcohol Content?

The most commonly used formula to calculate Blood Alcohol Content is:
%BAC = (A x 5.14/W x r) – .015 x H, where

  • “A” is the number of liquid ounces of alcohol consumed. For example, the standard 5% beer would be .60 (12 x 0.05)
  • “W” is the person’s weight in pounds
  • “r” is the distribution ratio (.66 for women, and .73 for men)
  • “H” is the number of hours in which the alcohol was consumed

However, this formula is not 100% accurate when used to calculate Blood Alcohol Content. Several complex factors must be taken into consideration to accurately calculate Blood Alcohol Content, such as physical and emotional health, as well as the consumption of food.

BAC Calculator
Basic Details
time since first drink
Elapsed time - required Enter the hours since you consumed your first drink for increased accuracy.
your weight
Your weight - required Enter your closest weight value. This is important to establish your current BAC level.
Sex, time & weight fields all required to calculate.
Drink Selector
Spirits (Single) 40% - 1.5oz
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Spirits (Double) 40% - 3oz
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Small Wine 12% - 4.2oz
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Medium Wine 12% - 5.9oz
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Large Wine 12% - 8.5oz
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Beer (12 fl oz) 5% - 12oz
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Beer Light (12 fl oz) 4% - 12oz
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Beer (US Pint) 5% - 16oz
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clear drinks
BAC Results
0.0000 %BAC
Time until 0.00% BAC
Time until 0.08% BAC
Time unavailable (BAC > 0.500%)

BAC Calculator Disclaimer

This BAC calculator is for informational purposes only. This tool does not provide a 100% accurate reading of an individual’s blood alcohol content because it cannot account for a number of variables that impact one’s BAC. By using this calculator, you acknowledge that any calculations are not scientifically reliable and may contain inaccuracies, and we expressly exclude liability to the fullest extent permitted by law. We strongly recommend that you do not operate a motor vehicle if you have consumed any alcohol.”