Body Mass Index (BMI) is a number calculated from your height and weight. It is used as a simple screening tool to identify potential weight problems in adults. BMI = weight(kg) / height(m)².

What is a healthy BMI range?

According to WHO: Under 18.5 = Underweight, 18.5–24.9 = Normal weight, 25.0–29.9 = Overweight, 30.0 and above = Obese. These ranges apply to adults 18 and older.

Is BMI an accurate measure of body fat?

BMI is a useful population-level screening tool, but it does not directly measure body fat percentage. It can misclassify very muscular people as overweight, or underweight people who carry excess fat. It should be one factor among many in any health assessment.

Does BMI apply to children?

BMI is calculated differently for children and teenagers using age- and sex-specific growth charts. This calculator is designed for adults aged 18 and over.

BMI Calculator

Calculate your Body Mass Index (BMI) in metric or imperial units instantly.

Height (cm)

Weight (kg)

BMI Categories

< 18.5Underweight

18.5 – 24.9Normal weight

25 – 29.9Overweight

≥ 30Obese

About BMI Calculator

Free online BMI calculator. Calculate your Body Mass Index using metric (kg/cm) or imperial (lb/ft/in) units. Displays your BMI score, weight category (Underweight, Normal, Overweight, Obese), and a visual chart showing where your result falls according to WHO guidelines. Results are instant and entirely client-side.

How to Use BMI Calculator

Select your unit system: Metric (kg and cm) or Imperial (lb and ft/in).
Enter your height and weight in the provided fields.
Your BMI score and weight category appear instantly.
Read the color-coded chart to see where your BMI falls on the WHO scale.

Frequently Asked Questions

What is BMI?: Body Mass Index (BMI) is a number calculated from your height and weight. It is used as a simple screening tool to identify potential weight problems in adults. BMI = weight(kg) / height(m)².
What is a healthy BMI range?: According to WHO: Under 18.5 = Underweight, 18.5–24.9 = Normal weight, 25.0–29.9 = Overweight, 30.0 and above = Obese. These ranges apply to adults 18 and older.
Is BMI an accurate measure of body fat?: BMI is a useful population-level screening tool, but it does not directly measure body fat percentage. It can misclassify very muscular people as overweight, or underweight people who carry excess fat. It should be one factor among many in any health assessment.
Does BMI apply to children?: BMI is calculated differently for children and teenagers using age- and sex-specific growth charts. This calculator is designed for adults aged 18 and over.

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BMI Calculator

Calculate your Body Mass Index (BMI) in metric or imperial units instantly.

Height (cm)

Weight (kg)

BMI Categories

< 18.5Underweight

18.5 – 24.9Normal weight

25 – 29.9Overweight

≥ 30Obese

About BMI Calculator

How to Use BMI Calculator

Select your unit system: Metric (kg and cm) or Imperial (lb and ft/in).
Enter your height and weight in the provided fields.
Your BMI score and weight category appear instantly.
Read the color-coded chart to see where your BMI falls on the WHO scale.

Frequently Asked Questions

What is BMI?: Body Mass Index (BMI) is a number calculated from your height and weight. It is used as a simple screening tool to identify potential weight problems in adults. BMI = weight(kg) / height(m)².
What is a healthy BMI range?: According to WHO: Under 18.5 = Underweight, 18.5–24.9 = Normal weight, 25.0–29.9 = Overweight, 30.0 and above = Obese. These ranges apply to adults 18 and older.
Is BMI an accurate measure of body fat?: BMI is a useful population-level screening tool, but it does not directly measure body fat percentage. It can misclassify very muscular people as overweight, or underweight people who carry excess fat. It should be one factor among many in any health assessment.
Does BMI apply to children?: BMI is calculated differently for children and teenagers using age- and sex-specific growth charts. This calculator is designed for adults aged 18 and over.