国际标准号数，内直径尺寸，手指周长？怎样换算呢？地大饰家为您图文真实演示，怎样测量，换算号数、周长、直径、换算全过程。

                         步骤一：用“细线”测量手指“佩戴部位”的周长。如下图所示：



                                      步骤二：用直尺测量细线长度，得到手指的周长。按以下表格换算尺寸。如下图所示：
                                                号数  内直径(MM) 周长(MM)
                                                                        10       15.6       50.5
                                                                        11       16.1       52.0
                                                                        12       16.9       53.0
                                                                        13       17.0       53.5
                                                                        14       17.7       55.5
                                                                        15       18.0       56.5
                                                                        16       18.2       57.0
                                                                        17       18.3       57.5
                                                                        18       18.5       58.0
                                                                        19       18.8       59.0
                                                                        20       19.4       61.0