Body mass index (BMI) and waist circumference are two measurements to identify if you are at increased risk of developing health problems because of your weight. BMI is a simple calculation that measures your weight relative to your height.

Body mass index may not be accurate for those who are :

• Over the age of 65
• Of certain racial and ethnic groups
• Naturally very lean or very muscular
• Under 18 or not finished growing

Metric Imperial BMI Formula

The metric bmi formula accepts weight measurements in kilograms & height measurements in either cm’s or meters.
1 meter = 100cms
meters² = meters * meters

Table : Metric BMI Formula

BMI =
( kg/m² ) weight in kilograms ———————————— height in meters²

Imperial BMI Formula

The imperial bmi formula accepts weight measurements in pounds & height measurements in either inches or feet.
1 foot = 12 inches
inches² = inches * inches

Table : Imperial BMI Formula

BMI =
( kg/m² ) (weight in pounds * 703 ) ———————————— height in inches²

BMI Categories:

• Underweight = <18.5
• Normal weight = 18.5-24.9
• Overweight = 25-29.9
• Obesity = BMI of 30 or greater

The second measurement is waist circumference. It may be easier to have someone else take your waist measurement. Place the tape measure half way between your hip bone and your lowest rib. This will be about 2 inches above your belly button. Ensure that the tape measure is level all the way around. Take a deep breath, breathe out and measure.

Men with a waist circumference of more than 40 in or 102 cm and women with a waist circumference of more than 35 in or 88 cm are at increased risk of developing health problems such as type 2 diabetes, heart disease and high blood pressure.

Put the two measurements together to determine your overall risk. Even for those with a healthy BMI an elevated waist circumference will indicate an increased risk. Other factors that put you at increased risk are:

• High blood pressure
• High cholesterol
• High triglycerides
• High blood sugar
• Not being physically active
• Cigarette smoking

The risks for each individual needs to take into account other factors such as lifestyle habits, fitness level and the presence of other health conditions. Talk to your doctor if you are at increased risk and need to lose weight. People who are overweight or obese have a greater chance of developing high blood pressure, high cholesterol, type 2 diabetes, stroke and certain types of cancer. Even a small weight loss, just 10% of your current weight will help to lower your risk of developing those diseases.