Abstract: A writing instrument that includes tables and operational elements for calculating the Body Mass Index (BMI) of a person. In general, the BMI of a person is calculated based on the weight and height of the person. The present invention is a writing instrument which combines a writing instrument with a measuring device in one lightweight and commonly used type of device, thereby freeing the user of the need to refer to complicated charts or other technical materials. The writing implement has a first end which includes the writing tip portion and a second end which includes the tables and operational elements used to calculate the individual's BMI.