Hallo! How much do the hair weight? How much do we need to one person if I sew it in. Sorry but my English is sooo bad

This is for 1 single hand tied weft. Weights are 14" = 10.6g 18" = 3g 22" = 14.4g. It will depend on your design. Typically 1-3 packs of hair for a full installation. Packs of hair include different numbers of bundles depending on the length. 14" = 10 bundles 18" = 8 bundles 22" = 6 bundles This product is just 1 bundle.