It is not advisable to lengthen the hair more than twice the original length of the hair.If you have never gone with hair extensions, I do not advise you to extend very long hair for the first time. The most “comfortable” length is 16 inches. Approximately to the shoulder blades or slightly below."Why?", You ask ..Firstly, long hair is not for everyone. It depends on the shape of the face.Secondly, the length of your hair should be at least shoulder-length so that hair extensions 20 inches or more in length look natural and the weight of the hair extensions does not harm your hair.Third, grooming ha with such long hair is more difficult.Fourth, with hair lengths of 23 inches or more, it is very uncomfortable in everyday life.