For your sew-ins with Closure you will need 2 bundles and a closure if the lengths are between 10' to 16' because more the bundle is short ,more it full.
Example you can do 10'10' or 10'12' / 12'12' 0r 12' 14' / 14'14' or 14'16 / 16'16'
After 16' you will need 3 bundles and a closure because more it longer more it less full for your sew ins. Example you can do 16'18'20'
18'20'22' / 20'22'24' / 22'24'26' / 24'26'28' / 26'28'30 / 28'30'30' or you can do 3 bundles with the same lengths like 20'20'20' or 30'30'30'
Some Clients liked their hair very full so they use 4 Bundles , but the most popular Clients used 3 Bundles with a closure for their sew-ins.
But it up to you at least you have some guidance and choices for your next weave.
Enjoy Au Revoir, Bye until next Time God Bless .