I developed an iOS application in Swift to track and visualize Blood Alcohol Concentration (BAC) levels in real time using the Widmark formula. Upon launch, the user provides their gender and weight, and the app calculates BAC based on the number of standard drinks consumed as well as the elapsed time since starting to drink. A “Start” button records when the user’s drinking session begins, while a “+” button increments the count of standard drinks.

To convey BAC visually, the app displays a dynamic circle whose size and color intensify as the user’s BAC increases; the warmer the color and larger the circle, the higher the estimated BAC. Additionally, an outer ring indicates the recommended upper limit, helping users recognize when they are approaching unsafe levels. This intuitive, color-coded visualization encourages self-awareness and promotes responsible decision-making. By leveraging Swift’s robust libraries and a thoughtful user interface, the BAC tracker provides an engaging, real-time experience that helps users stay informed about their alcohol consumption.