To provide a body weight measuring device and a body weight measuring system that can be handled easily and can be used repeatedly even by a user without specialized measurement technology. This body weight measurement device 10 is configured by having: a main body part 1 that is configured by a stretchable material and that forms a portion other than a sole portion of a piece of footwear； a sole part 2 that is configured by a stretchable material and that forms a sole portion having a footwear shape； a wearing opening part 3 that forms an opening that serves as a wearing opening for a sock； and a measurement processing part 4 that executes processing and the like of measurement values for measuring the size and shape of the foot of a user.[課題] 提供即使為不具專業量尺寸技術的使用者亦可簡單處理，且可反覆使用的身體測定裝置及身體測定系統。 [解決手段] 身體測定裝置(10)係構成為具有：以可伸縮素材所構成且形成腳穿物的腳底部分以外的部分的本體部(1)；以可伸縮素材所構成且形成腳穿物形狀的腳底部分的腳底部(2)；形成成為襪子穿著口的開口部的穿著口部(3)；及執行使用者的腳的尺寸及形狀的測定值的處理等的測定處理部(4)。
