BMI Calculator
Calculate your Body Mass Index (BMI) to assess whether your weight is healthy for your height.
How it works
BMI is calculated using the formula: BMI = weight (kg) ÷ height² (m²). For example, if you weigh 70 kg and are 175 cm tall, your BMI is 70 ÷ (1.75 × 1.75) = 22.9, which falls in the Normal weight range. The World Health Organization classifies BMI into four categories: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), and Obese (30 and above).
Example
A person who weighs 80 kg and is 170 cm tall has a BMI of 27.7, placing them in the Overweight category. Their healthy weight range would be between 53.5 kg and 72.0 kg. This is a screening tool only — a doctor should assess your overall health.
Frequently asked questions
Is BMI an accurate measure of health?
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, age, or fat distribution. Athletes may have a high BMI due to muscle, while older adults may have a healthy BMI with excess body fat. Always consult a healthcare professional for a full health assessment.
What is a healthy BMI range?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. BMI below 18.5 indicates underweight, 25–29.9 indicates overweight, and 30 or above indicates obesity. Children and teenagers use different age-specific BMI charts.
Can I use this calculator in pounds and inches?
This calculator uses kilograms and centimeters. To convert: divide your weight in pounds by 2.205 to get kilograms, and multiply your height in inches by 2.54 to get centimeters.
Does BMI apply to children?
BMI is calculated the same way for children, but it is interpreted differently. For ages 2–19, BMI is compared to growth charts and expressed as a percentile relative to children of the same age and sex. Our calculator is designed for adults 20 and older.
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