How is BMI calculated?

BMI = weight (kg) ÷ height² (m²). For example, if you weigh 75 kg and are 1.75 m tall: 75 ÷ (1.75 × 1.75) = 24.5.

What are the BMI categories?

Is BMI an accurate measure of health?

BMI is a useful screening tool but does not account for muscle mass, bone density, fat distribution or other individual factors. Consult a healthcare professional for a comprehensive assessment.

What is a healthy BMI range?

A BMI between 18.5 and 24.9 is considered normal weight. However, the healthy range can vary slightly for different age groups and ethnicities.

BMI Calculator

Calculate your Body Mass Index (BMI) from weight and height. See your BMI category and healthy weight range.

Weight (kg)Height (cm)

Body Mass Index (BMI) is the ratio of weight to height that gives a rough estimate of whether your weight is in a healthy range. BMI is calculated as weight (kg) / height (m)².

How the calculator works and what it’s for▾

BMI categories

Under 18.5 = underweight, 18.5–24.9 = normal, 25–29.9 = overweight, 30 or over = obesity. These apply to adults (18+); children use age- and sex-specific charts.

What BMI doesn’t tell you

BMI doesn’t distinguish muscle from fat or account for where fat sits. A muscular person can have an "overweight" BMI with low body fat. Also look at waist circumference and body fat percentage.

Example

A person 175 cm tall weighing 75 kg: BMI = 75 / 1.75² ≈ 24.5 → normal. The healthy weight range for 175 cm is about 57–76 kg.

Tips

Use BMI as a guide, not the only measure. Waist circumference (over 100 cm for men, 90 cm for women) indicates abdominal fat, which is riskier. Consult a doctor if unsure.

🔄 Reviewed June 2026