使用多种分类标准计算你的身体质量指数（BMI）。获取健康建议和理想体重范围。纯客户端处理。
身体质量指数（BMI）是一个常用的体重与身高比例指数，用于分类成年人的体重不足、超重和肥胖。它定义为一个人的体重（千克）除以身高（米）的平方（kg/m²）。此计算器支持多种国际分类标准并提供个性化的健康建议。所有计算都在你的浏览器中进行 — 数据不会发送到任何服务器。
BMI (Body Mass Index) is a simple measurement of body fat based on your height and weight. It is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). This calculator handles both metric and imperial units automatically.
According to the WHO standard, a healthy BMI range is 18.5 to 24.9. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. Asian and China standards use slightly lower thresholds because research shows health risks begin at lower BMI values for these populations.
Different populations have different body compositions and health risk profiles. The WHO standard is designed for Western populations, while Asian and China standards account for the fact that people of Asian descent often experience obesity-related health risks at lower BMI values. This calculator lets you compare all three standards.
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, age, sex, or fat distribution. Athletes with high muscle mass may have a higher BMI despite low body fat. For a complete health assessment, consult a healthcare provider.
BMI is a weight-to-height ratio that estimates body fat. Body fat percentage is the actual proportion of fat in your body. BMI is easier to calculate and widely used, but body fat percentage provides a more accurate picture of body composition. Tools like body fat calipers or DEXA scans measure body fat percentage directly.
This calculator is designed for adults (18+). For children and teens, BMI is interpreted differently based on age and sex using percentile charts. Consult a pediatrician for accurate BMI assessment in children.
For general health monitoring, checking your BMI once every 3 to 6 months is sufficient. If you are actively working on weight management or fitness goals, you may check monthly. Daily changes are not meaningful — focus on long-term trends.
Consult a healthcare provider for personalized advice. General recommendations include adopting a balanced diet rich in vegetables and lean proteins, increasing physical activity (at least 150 minutes of moderate exercise per week), getting adequate sleep, and managing stress. Small, sustainable changes are more effective than extreme diets.