Quote of the Day
Your time is limited, so don't waste it living someone else's life.
— Steve Jobs
Back in 2011, I wrote a blog post that goes into the details on how the Blood Alcohol Content (BAC) versus drinks/time/gender are computed (Figure 1). These charts tell people how much they can drink and still stay under the BAC limits for driving under the influence. These charts are for a typical drinker and the actual BAC value will vary by person.
A reader, Megan Sweeny, wrote a very interesting comment to my original post that included a link to a Google sheet she created that applied the Widmark formula to a person that drinks at a fixed rate to investigate the validity of the following rule of thumb:
Your BAC level will remain within safe limits if you consume only one standard drink per hour.
The basis of most BAC charts is the Widmark formula. Megan used the Widmark formula to test the rule of the thumb mathematically. Her approach was to:
- Assume the person takes a drink at the top to the hour (1:00, 2:00, 3:00, etc).
- Compute the BAC one hour after consumption.
- Draw charts to illustrate how the drinker's BAC varies with time.
Megan's model show that a 150 lb male following the rule of thumb eventually will exceed the legal limit. Since I use this blog as a repository for my Excel work, I have made an Excel version of Megan's work that you can access here.
From my standpoint, no one should ever drive after drinking. However, this was an excellent use of spreadsheet to model a common rule-of-thumb.
Nice work Megan.