A new smartphone application estimates a person’s blood-alcohol concentration (BAC). The app is designed to help a person decide if they should avoid driving because they’ve had too much to drink.

A person using the app, called “Show Me My Buzz,” enters information including how many drinks they’ve had, their weight and their gender, KMOX reports. The app, launched by the Missouri Department of Transportation, then estimates the person’s BAC.

If the app indicates the person has exceeded Missouri’s legal BAC limit of .08, it will provide the phone number of a local taxi company. The state Department of Transportation points out the app only provides an estimate of a person’s BAC, which also can be influenced by how much food he or she has in their stomach, the medications they are taking, as well as other health and psychological factors. “Many establishments that serve alcohol, serve portions larger than the standard drink size,” notes the website for the app.