According to the Centers for Disease Control and Prevention, an adult person's ideal weight is calculated by dividing their weight by the square of their height and then comparing the number to a standard range of values. This number is called a person's Body Mass Index.
The metric system formula for BMI used by the CDC is weight in kilograms divided by the square of the height in meters. Below is an example for a person who weighs 60 kilograms and is 1.6 meters tall.
BMI = weight in kilograms ÷ [height in meters]²
BMI = 60 ÷ [1.6]²
BMI = 23.4
To determine BMI using pounds and inches, the formula used by the CDC is weight in pounds divided by the square of the height in inches, multiplied by a conversion factor of 703. Below is an example for someone who weighs 132 pounds and is 63 inches tall.
BMI = [weight in pounds ÷ (height in inches)²] x 703
BMI = [132 ÷ (63)²] x 703
BMI = 23.4
The ideal BMI is between 18.5 and 24.9. A BMI below 18.5 is underweight, while a BMI between 25.0 and 29.9 is overweight. A BMI over 30.0 is a sign that a person is obese.
Always remember to consult your doctor before starting any weight-loss regimen.