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Calculation Algorithm - Calculation of Residual Alcohol in Blood

Here is a brief description of the algorithm used in the application (online alcohol test, "breathalyzer") for calculating residual alcohol in the blood. First, let's talk about the beverages that can be selected in the alcohol test (breathalyzer) from the wide range offered by the application. In the breathalyzer, an alcoholic beverage is characterized by two basic values. The first value is the volume, as seen in the formula below, and the second value is the alcohol content. These values can be substituted into the "mass" formula to determine the amount of alcohol in the drink.

mass = (volume * alcohol content * 0.8) / 100 [g]

This "mass" formula provides us with the amount of pure ethanol in grams present in the beverage. As for the units, the volume is given in milliliters, and the number 0.8 represents the density of ethanol. The calculation of promille (blood alcohol concentration) is then performed using the "promille" formula shown below.

promille = mass / (weight * r) [g/kg]

In this formula, the first parameter represents the mass of ethanol in grams obtained from the previous "mass" formula. The second value is the weight, which indicates the body weight of the consumer in kilograms for calculating their blood alcohol level. As we can see, the last value is "r," which denotes the water ratio in the body. As someone might suspect, the value for men is different from that for women. For men, this value is 0.7, while for women, it is 0.6. These values determine the amount of alcohol that is eliminated per hour per kilogram of body weight. Using these values, we obtain the result of the "promille" formula. It has long been known that the human body has the ability to metabolize alcohol. The decrease in blood alcohol concentration can be observed over an hourly time interval, and it is represented as beta in the "mass" formula. We have described the values in the formulas, and as a final note, the "mass" formula yields the amount of alcohol that the body can metabolize in one hour.

mass = weight * beta [g]

The resulting mass indicates the total amount of ethanol in grams that the body can metabolize in one hour. The weight of the consumer, as in the previous formula, is given in kilograms, and the beta constant, as we mentioned earlier, represents the metabolism of alcohol from the body over the necessary period. As the last step, if you want to try this free application (Breathalyzer "Alcohol Tester") in the mobile version, you can download it for free using the links below.

Breathalyzer app on Google Play

Breathalyzer app on App Store

Thank you for using our application "Breathalyzer" and for your feedback and comments. If you want to switch to the web version of this breathalyzer, simply click on "Alcohol Test - Online Breathalyzer" and you can immediately calculate your blood alcohol content and observe its subsequent elimination.


The calculations used by various applications to determine residual alcohol in the blood should never be relied upon or used by users as a basis for deciding whether or not to drive! These calculations are influenced by many factors, and therefore, the actual deviation can sometimes be significant. If someone needs to determine their residual alcohol in the blood, they should undoubtedly use the services of reliable digital breath alcohol testers! This will prevent unexpected fines for residual alcohol while driving and help reduce the already high number of alcohol-related accidents caused by impaired drivers.

If you are interested in an alcohol tester and are unsure which one to choose from the wide range of breathalyzers on the market, we can help you. Our recommended favorite is Alteon, a reliable, high-quality, affordable breathalyzer with many advantages and features compared to other breathalyzers. You can see for yourself; more information can be found here: Alteon.