For a full install with no closure or frontal and/or minimal leave out, you will need 3 bundles if you are using lengths shorter than 22 inches. For hair measuring 22 inches and up, it is recommended to use 4 bundles. For lengths 30 inches and longer, you will need 5 bundles.When using a lace closure, between 3-4 bundles are recommended for a voluminous look although 3 bundles can complete the install.When using a lace frontal, between 3-4 bundles are recommended for a voluminous look although 2-3 bundles can complete the install.