BMI计算器
计算身体质量指数，了解体重和身高的关系
What is BMI and how do you calculate it?
BMI (Body Mass Index) is calculated by dividing your weight in kilograms by your height in meters squared: BMI = kg/m². A BMI of 18.5-24.9 is considered normal weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.
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Create Free Account什么是BMI？
BMI（身体质量指数）是根据身高和体重来评估体脂的简单方法，计算公式是体重（公斤）除以身高（米）的平方。虽然BMI不能直接测量体脂，但能帮你初步判断体重是否在健康范围内。全球医生都用BMI作为筛查工具，来识别可能的体重相关健康问题。
BMI怎么算？
BMI公式：体重（公斤）÷ 身高（米）²。英制单位要乘703：体重（磅）÷ 身高（英寸）² × 703。结果分为几档：偏瘦（低于18.5）、正常（18.5-24.9）、偏胖（25-29.9）和肥胖（30以上）。这些分类能提示潜在健康风险，但也要结合肌肉量和身体成分等个人因素来看。
BMI的局限性
BMI虽然好用，但有局限。它分不清肌肉和脂肪，所以运动员或肌肉发达的人BMI可能偏高但其实很健康。它也不考虑年龄、性别、种族或脂肪分布位置。想全面了解健康状况，建议结合腰围、体脂率等其他指标一起看。
BMI vs BMR: What's the Difference?
BMI measures your weight relative to height to categorize your body size. BMR measures the calories your body burns at rest. BMI tells you if you're at a healthy weight; BMR tells you how much energy your body needs. Use both together for a complete picture of your health.
Frequently Asked Questions
What is a healthy BMI range?
A healthy BMI range is between 18.5 and 24.9. This range is associated with the lowest risk of weight-related health problems. However, BMI is just one indicator and should be considered alongside other health markers.
Is BMI accurate for athletes and muscular people?
BMI can overestimate body fat in athletes and muscular individuals because it doesn't distinguish between muscle and fat mass. If you have significant muscle mass, consider using body fat percentage measurements for a more accurate assessment.
How often should I check my BMI?
Checking your BMI monthly is sufficient for most people. Since BMI changes gradually with weight changes, weekly checks are unnecessary. Focus on long-term trends rather than daily fluctuations.
What should I do if my BMI is too high or too low?
If your BMI falls outside the normal range, consult a healthcare professional. For high BMI, focus on a balanced diet and regular exercise. For low BMI, ensure adequate nutrition and caloric intake. A personalized workout plan can help you reach a healthy weight.
Does BMI differ by age and gender?
Standard BMI categories apply to adults aged 20 and older regardless of gender. For children and teens, BMI is calculated the same way but interpreted using age- and sex-specific percentiles. Older adults may have slightly different healthy ranges.