---
title: "BMI Calculator — WHO, Japan, China, Asia-Pacific Standards Compared"
description: "Calculate your BMI and instantly compare your result under WHO, Asia-Pacific, Japanese (JASSO), and Chinese (WGOC) standards. See why the same BMI means different things in different countries."
url: "https://worldcalculators.org/calculators/bmi/"
canonical: "https://worldcalculators.org/calculators/bmi/"
---

# BMI Calculator

Calculate your BMI and instantly compare your result under WHO, Asia-Pacific, Japanese (JASSO), and Chinese (WGOC) standards. See why the same BMI means different things in different countries.

## Quick answer

Use this calculator if you want the same BMI arithmetic scored under WHO, Japan (JASSO), Asia-Pacific and China (WGOC) at once. Skip it if you are under 18, pregnant, or a high-muscle athlete — BMI is a population screen, not a diagnosis. WHO healthy BMI: 18.5–24.9. Japan classes BMI ≥25 as obese (WHO’s “overweight”). Asia-Pacific overweight starts at 23. A BMI of 26 is overweight (WHO), obese grade 1 (Japan), and obese class I (Asia-Pacific).

## How is BMI calculated?

BMI is weight in kilograms divided by height in metres squared. In imperial units it is pounds times 703, divided by height in inches squared. Every country on this page uses that same arithmetic — the only thing that changes is the labelled category, which is why a BMI of 26 can be overweight in the US and obese in Japan.

## What BMI is obese in Japan versus WHO?

Japan’s JASSO guideline labels BMI 25 and above as obese. WHO labels 25–29.9 as overweight and 30+ as obese. Asia-Pacific (WPRO/IASO) starts overweight at 23 and obesity at 27.5. China (WGOC) uses overweight at 24 and obesity at 28. Check the table — the formula did not change; the public-health cut-off did. Sources: WHO 2000, WPRO/IASO 2000, JASSO 2011, WGOC 2004, reviewed June 2026.
Sources: WHO 2000, WPRO/IASO/IOTF 2000, JASSO 2011, WGOC 2004.

## Why does Japan use a different BMI standard?

JASSO set obesity at BMI 25 because East Asian populations tend to carry more body fat, and to develop type 2 diabetes and metabolic syndrome, at a lower BMI than European-descent populations. The lower cut-off is a clinical-risk choice, not a translation quirk. It is also why Japan’s official obesity rate looks low: the same body can be “overweight” in New York and “obese grade 1” in Tokyo.
At the same BMI, East Asian people typically have a higher percentage of body fat than people of European descent.

## Who should skip this BMI calculator?

Skip it if you are a child or teenager (ages 2–19 need percentile charts, not adult cut-offs), if you are pregnant, or if you have high muscle mass — BMI cannot tell fat from muscle. Use it as a first screen, then add waist circumference and a clinician. The UK NHS still uses WHO cut-offs for most adults but recommends Asia-Pacific-like intervention thresholds for some South Asian, Black African and Caribbean patients.
A muscular athlete may have BMI 28 without excess body fat. Bodybuilders routinely score "obese" by BMI.

## Which country BMI pages are worth opening?

We keep translated and country-specific BMI pages that add local authority guidance. Thin English name-swap URLs redirect here so they cannot dilute the canonical tool.

## Sources & Methodology

BMI is weight (kg) divided by height (m) squared. We use the WHO international cut-offs as the default and surface country-specific thresholds (e.g. the lower overweight cut-offs used across much of Asia) where national bodies differ.

Source: https://worldcalculators.org/calculators/bmi/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.