Body Mass Index (BMI) is a number calculated from a person's weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems For details on calculating your BMI manually, follow the steps below Step 1: Weigh & Measure Weigh yourself on your bathroom scale. Note: the following formula is calculated in Kg Measure your height in inches using the yardstick or measuring tape. Stand against the wall and use a pencil to make a mark at the top of your head, then measure Step 2: Calculating BMI Manually Use the pencil, paper and calculator to perform the following BMI calculation Take your height in cm and square the number. In other words, multiply the number of cm by the same number of cm Divide your weight in Kg by the second figure. The second figure is your height in cm squared The answer is your body mass index Step 3: The Results Judge your personal BMI result against the following scale: A BMI of less than 18.5 means you are under weight A BMI between 18.6 and 24.9 indicates you are at a healthy weight A BMI between 25 and 29.9 suggests you are overweight for your height A BMI of 30 or greater indicates obesity If you are obese, consider consulting a doctor or losing weight Also, you can observe the following figure to know your BMI indication References cdc.gov wikihow.com