SQL Server has default value for fill factor is Zero (0). The fill factor is implemented only when the index is created; it is not maintained after the index is created as data is added, deleted, or updated in the table. When creating an index, you can specify a fill factor to leave extra gaps and reserve a percentage of free space on each leaf level page of the index to accommodate future expansion in the storage of the table’s data and reduce the potential for page splits.
I like my fill factor to 90 (Why? I like it!) I use sp_configure to change the default fill factor for the SQL Server.
sp_configure 'show advanced options', 1 GO RECONFIGURE GO sp_configure 'fill factor', 90 GO RECONFIGURE GO