noun
body composition monitor; body fat scale
A scale that measures body fat percentage, muscle mass, and other metrics beyond simple weight.
新しい体組成計で毎日体重と体脂肪率を測っています。
I measure my weight and body fat percentage every day with my new body composition monitor.
体重計 is a standard bathroom scale that only measures weight, while 体組成計 provides additional body composition data.
Compound of 体 (body), 組成 (composition), and 計 (meter). A modern technical term for a body composition analyzer.