The size allocation decisions you make are important, because it is difficult to reclaim storage space after it has been assigned. You can always add space; however, you cannot de-allocate space that has been assigned to a database, unless you drop the database first.
You can estimate the size of the tables and indexes for your database by using sp_estspace or by calculating the value. See Chapter 15, “Determining Sizes of Tables and Indexes,” in the Performance and Tuning Guide for instructions.
