Standard: The most standard value is 22. The ideal weight range is 10% (19.8 ~ 22.4). If it is larger than the range, it will be too fat; It's too thin without it.
For example, suppose your height is 175 cm and your weight is 80 kg, and your body mass index = 80/1.75×1.75 = 26.12 is already overweight!