A promotional writing instrument includes an elongated barrel having opposite first and second ends, a writing element located at the first end, and an electronic body mass index (BMI) calculator located at the second end that is configured to display a BMI number in response to user entry of weight and height data. The BMI calculator includes a housing having opposite front and rear faces, opposite first and second sides, and a free end portion. A display is viewable through the housing front face. A processor is disposed within the housing that calculates and displays, via the display, a BMI number in response to user entry of weight and height data. A user control is operably connected with the processor and located adjacent the display.