People’s BMI (Body Mass Index) is the sum of their weight in kilograms (or pounds) and their height in meters (or feet) (or feet). A high body mass index (BMI) may be a sign of excessive body fat. An individual may have an abnormally high BMI, but this does not mean that they are obese or that they are unhealthy.
English-System BMI Calculation (lbs)
When utilizing English measurements, decimal values must be used for ounces (oz) and fractions. Then, divide your weight in pounds (lb) by your height in inches (in) squared and multiply by 703.
You can round to one decimal place if your handheld calculator includes a square function and you divide the weight (lb) by the height (in).
If you don’t have a square function on your calculator, divide the weight by the height Square, multiply by 703, then round to the next decimal place.
NOTE: The CDC Clinical Growth Charts use this formula; it will be used in this module’s calculations as well).
Let’s calculate Sam’s BMI using the English numeric system. His weight is 60 pounds and 4 ounces and his height is 40 1/2 inches.
Convert ounces and fractions to decimals:
- Weight of 60 lbs and 4 oz = 60.25 lbs (16 ounces = 1 pound so 4 oz/16 oz = 0.25).
- Height = 40.5 in.
- Calculation: BMI=(60.25 lbs / 40.5 in x 41.5 in) x 703 = 25.8
BMI Range for Understanding Categories
How is BMI used?
BMI is a screening tool, however, it does not diagnose an individual’s body fatness or health. A healthcare provider will do additional tests to evaluate if BMI is a health risk. Skinfold thickness measurements, dietary, physical activity, and family history evaluations are examples of such exams.
How is BMI interpreted for adults?
BMI is calculated using conventional weight status categories for adults aged 20 and up. These categories apply to men and women of all ages and physical shapes.
|18.5 – 24.9||Healthy Weight|
|25.0 – 29.9||Overweight|
|30.0 and Above||Obesity|
As an example, here are the weight and BMI ranges for a 5’9″ person, as well as the weight status categories.
|Weight Range||BMI||Weight Status|
|124 lbs or less||Below 18.5||Underweight|
|125 lbs to 168 lbs||18.5 to 24.9||Healthy Weight|
|169 lbs to 202 lbs||25.0 to 29.9||Overweight|
|203 lbs or more||30 or higher||Obesity|