standard yarn weight system            yarn type (us) ply (uk , nz , au)  m / 100 g wraps per inch (wpi)
0                   0 or lace  thread , cobweb and lace          1 - 3 ply  600 - 800             18 + wpi
1              1 or superfine                 fingering              4 ply  400 - 480               14 wpi
2                   2 or fine                     sport              5 ply  300 - 400               12 wpi
3                  3 or light                        dk              8 ply  240 - 300               11 wpi
4                 4 or medium                   worsted             10 ply  120 - 240                9 wpi
5                  5 or bulky                     bulky             12 ply  100 - 130                7 wpi

Table as JSON:
{"standard yarn weight system":{"0":"0 or lace","1":"1 or superfine","2":"2 or fine","3":"3 or light","4":"4 or medium","5":"5 or bulky"},"yarn type (us)":{"0":"thread , cobweb and lace","1":"fingering","2":"sport","3":"dk","4":"worsted","5":"bulky"},"ply (uk , nz , au)":{"0":"1 - 3 ply","1":"4 ply","2":"5 ply","3":"8 ply","4":"10 ply","5":"12 ply"},"m \/ 100 g":{"0":"600 - 800","1":"400 - 480","2":"300 - 400","3":"240 - 300","4":"120 - 240","5":"100 - 130"},"wraps per inch (wpi)":{"0":"18 + wpi","1":"14 wpi","2":"12 wpi","3":"11 wpi","4":"9 wpi","5":"7 wpi"}}