How Accurate are BAC Calculating Apps - Expert Article

In this article, Toxicologist, Michael J. Whitekus Ph.D. evaluates the accuracy of an App that is designed to calculate Blood Alcohol Concentration (BAC). He evaluates its accuracy and provides general impressions on its ability to educate individuals on alcohol consumption and accurately calculate BAC levels.

How accurate are blood alcohol Apps?

In the last several years there has been a rise in cell phone Apps for just about every activity, including Apps available for predicting your blood alcohol concentration (BAC). These Apps promise helpful information to keep your celebrations safe, but how accurate are they?

As a toxicologist I have reviewed many cases in which individuals were apparently unaware of their blood alcohol level. Since BAC measurement devices are virtually unavailable in bars and self-assessment by intoxicated individuals is notoriously unreliable, I was interested in evaluating one of the many Apps designed to track alcohol consumption and measure blood alcohol concentration. The App I evaluated was the AlcoDroid Alcohol Tracker, which is available for free on Android devices. My intent was to evaluate its accuracy and provide general impressions on its ability to educate individuals on alcohol consumption and calculate BAC levels. As a disclaimer, I have no business or financial connections with the AlcoDroid App. The App was chosen for this review because it came up number one when a blood alcohol concentration search was conducted on the Android Play Store.

App Input information:

The App asks for body weight and gender but does not ask for age or height, which are standard anthropometric values, used in BAC toxicology calculations. Age and body weight for men and body weight only for females are the most relevant anthropometric values when calculating BAC.

For the test:

  • I used a realistic 4th of July drinking situation in which an individual consumed seven 12 oz cans of 5% alcohol beer (e.g., Budweiser) by volume (one every half hour) over a 3 hour period (end of first drink to end of last drink).
  • In this test I varied the weight of male/female individuals (columns 1 and 4), and used the app to calculate the maximum % BAC (columns 2 and 5), and the time after last drink to reach a 0.08 % BAC value (columns 3 and 6).
  • I then compared these values to my calculated values in each situation and reported a % difference between the two values.
  • For this test I assumed each individual was a 25 year old 5’9’’ male or 5’2’’ female so I did not test varying age or height variables in this review. I assumed an alcohol elimination rate of 18 mg/dL/hr.

Summary of the data:

Looking at the male table below the App generated maximum % BAC values were quite accurate compared to my calculated values (<5% difference overall, column 2) while the App calculated time needed to recover to 0.08 % BAC was overestimated to a large degree (50-66% difference, column 3). For the female data the App underestimated the maximum % BAC values compared to my calculated values (14-25% difference, column 5) but then overestimated the time needed to recover to 0.08 % BAC (2-54% difference, column 6).


  • The App does communicate basic principles like the maximum % BAC as a function of drinks consumed and time to reach 0.08 % BAC if this value is exceeded.
  • The App calculated wait time values to reach 0.08 % BAC (probably one of the more important aspects of a BAC App) exceed 50% difference from my calculated values for several situations tested (although in every case tested the wait time values exceeded my calculated wait time value, which is good). This suggests that the App at times underestimates the alcohol elimination rate and generates a value far in excess of my calculated value.
  • The App generated male maximum % BAC values were close to my calculated values while there was a larger discrepancy between female generated maximum % BAC values and my calculated values.
  • The App provided some good general information but it was not accurate in all situations tested. Therefore, while I would not consider the AlcoDroid App a reliable scientific tool, I do believe that some people can benefit from the App as it provides a conservative time estimate for when individuals will return to legal BAC levels.

    The safest and best choice, if you are going to drink alcohol, is not to drive. In this industry we have all seen senseless injuries and lives lost.

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