The formulas and examples for allpages-locked tables are divided into two sets of steps:
Steps 1–6 outline the calculations for an allpages-locked table with a clustered index, giving the table size and the size of the index tree.
Steps 7–12 outline the calculations for computing the space required by nonclustered indexes.
These formulas show how to calculate the sizes of tables and clustered indexes. If your table does not have clustered indexes, skip steps 3, 4, and 5. Once you compute the number of data pages in step 2, go to step 6 to add the number of OAM pages.