With the body mass index (BMI) tape stmeasure you can monitor and assess changes to your body, including waist circumference and waist-to-hip ratio. Then use the calculator function to quickly determine BMI and obesity risk. FEATURES: Range: 0-150 centimeters / 60 niches in circumference; One-handed use and push button retraction; BMI calculator function; Colored tape for the classification of obesity risk; dual reading measures in metric and imperial (feet/inches) systems. How to To identify Obesity Risk: 1. Measure waist. Note that one side is for males, the other for females. The difference is the color-coded scale according to gender. 2. Use the following colors to identify obesity risk: Green = healthy, Orange = moderate risk, Red = obese ("central obese") and high risk of heart disease. To calculate BMI: 1. Using the dial, line up your weight (in kilograms) with your height (in meters). 2. See BMI reading in window to determine if you are underweight, healthy, or overweight, or very overweight.