The width of the trouser door is that it is one of the shapes of trousers thigh circumference.

For example, the female leg girth is about 58% of the hip, and the Leggings of the fitting pants are basically the same as the weight of the hips. They are all 6 centimeters, so they can be set to 16% net hips. The analogy is that the width of the tailgate is 15% of the net hips, the width of the tight trousers is 14% net hips, and the elastic tights are 13% net hips.

Then add and subtract 0.5 centimeters according to the thickness of the side.

So we can figure out the formula of the width of the slant gate. The thigh circumference is about 1/2 of the hips, plus the width of the hole door, then minus 2.5 centimeters.

Source: world clothing shoes and hats net