BMI計算機 — 体格指数

A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These thresholds are the same for men and women, though body composition differs between sexes.

BMI doesn't distinguish between muscle and fat mass, so athletes and very muscular people may be flagged as overweight despite having low body fat. It also doesn't account for age, ethnicity, or fat distribution. Use it as a general guideline, not a definitive health verdict.

Lowering BMI requires reducing body fat through a sustained calorie deficit, regular exercise (both cardio and resistance training), better sleep, and stress management. Aim for 0.5–1 kg of weight loss per week for sustainable results without muscle loss.

BMI is a ratio of weight to height squared — quick and easy but indirect. Body fat percentage measures actual fat tissue as a proportion of total body weight. For most people the two correlate reasonably well, but body fat is a more precise health indicator, especially for athletes.