YUCTS Tools

BMI Calculator (WHO and national cut-offs)

Calculate your BMI from height and weight and see the WHO adult category alongside the Japanese, Taiwanese and Chinese cut-offs. Metric and imperial units; a guide, not a diagnosis.

  • Runs in your browser (no upload)
Units

Not a diagnosisBMI is a rough indicator of body size, not a diagnosis. It does not reflect muscle mass, fat distribution, age or sex. These are adult standards and do not apply to children, teenagers or people who are pregnant or breastfeeding. If you are concerned about your health, talk to a doctor or another health professional.

Result

BMI 22.5 — Normal weight

BMI
22.5
WHO category
Normal weight

Category by standard

  • Standard: WHO (adults)

    Category: Normal weightBMI range of the category: 18.5 ≤ BMI < 25.0

  • Standard: Japan Society for the Study of Obesity (2022 guideline)

    Category: Normal weightBMI range of the category: 18.5 ≤ BMI < 25.0

  • Standard: Taiwan Health Promotion Administration (ages 18+)

    Category: Healthy weightBMI range of the category: 18.5 ≤ BMI < 24.0

  • Standard: China National Health Commission (WS/T 428—2013)

    Category: Normal weightBMI range of the category: 18.5 ≤ BMI < 24.0

BMI is weight (kg) ÷ height (m)², rounded to one decimal place before it is classified. The source of each standard is listed under "Data sources" at the bottom of the page.

How to use

  1. Choose metric (cm, kg) or imperial (ft, in, lb) units and enter your height and weight.
  2. Your BMI and its WHO category appear instantly.
  3. The table also shows the category and BMI range under the Japanese, Taiwanese and Chinese standards.

FAQ

How is BMI calculated?

Divide your weight in kilograms by the square of your height in metres. For 170 cm and 65 kg: 65 ÷ 1.7 ÷ 1.7 ≈ 22.5.

Why do the standards disagree?

Each organization or region draws the lines differently. WHO uses 25 and above for overweight and 30 and above for obesity. The Japan Society for the Study of Obesity counts 25 and above as obesity, Taiwan uses 24 for overweight and 27 for obesity, and China uses 24.0 for overweight and 28.0 for obesity.

Does BMI tell me whether I am healthy?

No. BMI only describes body size; it does not reflect muscle mass or where fat is stored. Other measures such as waist circumference are also used. Ask a doctor or another health professional if you are concerned.

How are imperial units converted?

With the exact factors 1 inch = 2.54 cm and 1 pound = 0.45359237 kg.

Notes & limitations

  • What you enter is processed only on this page and is not sent to YUCTS servers.
  • These are adult standards. They may not apply to children and teenagers (WHO takes age into account for them), people who are pregnant or breastfeeding, older adults or very muscular people.
  • The result is not a medical diagnosis. Ask a doctor or another health professional about your health.
  • Categories are based on the BMI rounded to one decimal place.
  • China has a separate standard for people aged 80 and over (WS/T 868—2025).

Data sources