Body mass index (BMI) calculator

BMI Calculator

BMI ranges

Underweight: less than 18.5 BMI

Healthy: 18.5 – 24.9 BMI

Overweight: 25 – 29.9 BMI

Obese: greater than 30 BMI

What is BMI?

Body Mass Index (BMI) is a method for determining whether you’re in a healthy weight range for your height.

BMI is a value derived from the weight and height of an individual. This value can be compared with suggested healthy ranges.

The limitations of BMI

While BMI can be a useful guide, it has some significant limitations.

BMI doesn’t take into account an individual’s age, gender or body composition.

Bone density isn’t considered and BMI doesn’t differentiate between muscle mass and fat. For example, a heavily muscled and very fit athlete could be classified as overweight or even obese, due to high bone density and significant muscle mass.

BMI is only applicable to adults, as children are still growing.

BMI is not a useful measure for pregnant women.

BMI is just part of the picture

BMI should always be considered in conjunction with other information, such as waist circumference.

How BMI is calculated

BMI is a value derived from the mass (weight) and height of an individual. The calculation for BMI is body mass (kg) divided by body height squared (m²).

The BMI calculation is expressed as: kg/m²