 The maximum hair length that is possible to reach is about 15 cm ( 6 in ) for infants ( below the age of 1 ) , about 60 cm ( 24 in ) for children , and generally 100 cm ( 40 in ) for adults . Documentation for decrease of the maximum length with age cannot be found in the literature . Some individuals can reach excessive lengths . Lengths greater than 150 cm ( 59 in ) are frequently observed in long hair contests . Xie <unk> had the longest documented hair in the world , measuring 5 @.@ 627 m ( 18 ft 5 @.@ 54 in ) in May 2004 . 
