BMI Calculator
Enter your height and weight to calculate your Body Mass Index (BMI) instantly and see your health category.
About This Tool
BMI (Body Mass Index) is a widely used international measure of whether a person's weight is healthy relative to their height. It is calculated as weight (kg) divided by the square of height (m), i.e. BMI = weight (kg) / height (m)².
This tool uses the Chinese adult BMI standard for classification: a BMI below 18.5 is Underweight, 18.5–23.9 is Normal, 24–27.9 is Overweight, and 28 or above is Obese. This standard better reflects the body characteristics of Chinese adults.
Besides the BMI value and its category, this tool also calculates the healthy weight range for your height, helping you set a target range for weight management.
Please note that BMI is a reference indicator and does not apply to everyone. For muscular athletes, pregnant women, the elderly and children, BMI may not accurately reflect body composition, so combine it with body-fat percentage and other metrics for a fuller picture.
How to Use
- Enter your height in centimeters in the "Height" field (e.g. 170).
- Enter your weight in kilograms in the "Weight" field (e.g. 65).
- Click the "Calculate BMI" button to instantly see your BMI value, health category and healthy weight range below.
FAQ
What is the formula for BMI?
BMI = weight (kg) / height (m)². For example, with a height of 1.7 m and a weight of 65 kg, BMI = 65 ÷ 1.7² ≈ 22.5, which falls in the Normal range.
What BMI is considered normal?
Under the Chinese adult standard: 18.5–23.9 is Normal; below 18.5 is Underweight; 24–27.9 is Overweight; 28 and above is Obese. Western standards differ slightly (Normal is 18.5–24.9).
Does a normal BMI mean I'm healthy?
Not necessarily. BMI only reflects the ratio of weight to height and cannot distinguish muscle from fat. Some people have a normal weight but a high body-fat percentage ("hidden obesity"), so it is also worth tracking waist circumference, body-fat percentage and other indicators.
Can children and pregnant women use this tool?
Not recommended. Children and teenagers should be assessed with age-specific growth charts, and weight change during pregnancy is a normal physiological phenomenon — the adult BMI standard does not apply to either group.
Will my data be uploaded or saved?
No. All calculations in this tool run locally in your browser. The height and weight you enter are never uploaded to any server.