Enter your weight and height to instantly calculate your BMI and find out your weight category according to WHO standards.
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Your BMI
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UnderweightNormalOverweightObese
How BMI is calculated
Body Mass Index (BMI) is a simple numerical measure of a person's body size, calculated from weight and height. It was developed in the 1830s by Belgian mathematician Adolphe Quetelet and is widely used as a screening tool for weight categories.
The WHO classifies BMI into four main categories: Underweight (<18.5), Normal weight (18.5–24.9), Overweight (25–29.9), and Obese (≥30). These thresholds may vary slightly by age, sex, and ethnicity.
Frequently Asked Questions
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese by the World Health Organization.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, age, or fat distribution. Athletes may be classified as overweight despite being healthy, while elderly people can have a normal BMI but excess body fat. Always consult a healthcare professional for a complete assessment.
What BMI is considered obese?
A BMI of 30 or above is classified as obese. The WHO further divides obesity into Class I (30–34.9), Class II (35–39.9), and Class III (40+, also called morbid obesity). Each class carries increasing health risks.