BMI and height

What is BMI

BMI, also known as Body Mass Index, is a body mass index that indicates the degree of obesity of a person calculated from height and weight.

Obesity increases the risk of diabetes and high blood pressure. Underweight can also be caused by malnutrition or chronic progressive disease.

Knowing the degree of obesity is useful for disease prevention and treatment.

BMI formula

BMI is calculated using the formula below.

BMI = Body weight(kg) ÷ (Height(m))2

Standard weight = (Height(m))2 x 22

BMI criteria

The formula for calculating BMI is universal, but the criteria for obesity differ from country to country.

Standards of the Japan Obesity Society

BMI index Condition
< 18.5 Underweight (thinness)
18.5 – 24.9 Normal range
25.0 – 29.9 Obese (Class I)
30.0 – 34.9 Obese (Class II)
35.0 – 39.9 Obese (Class III)
≥ 40.0 Obese (Class IV)

World Health Organization (WHO) standards

BMI index Condition
< 16.0 Severe thinness
16.0 – 16.9 Moderate thinness
17.0 – 18.4 Mild thinness
18.5 – 24.9 Normal range
25.0 – 29.9 Obesity
30.0 – 34.9 Obese (Class I)
35.0 – 39.9 Obese (Class II)
≥ 40.0 Obese (Class III)
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