Indexed sequential space requirement calculations can be summarized as follows:

1. How many blocks will fit on a track?

      Blocks = Track capacity / Length of blocks

2. How many overflow records will fit on a track?

      Overflow records = Track capacity / Length of Overflow records per track

3. How many index entries will fit on a track?

      Index entries per track = Track capacity / Length of index entries

4. How much space is left on the last track of the track index?

      Unused    = (Number of index entries per track)
      space     - (2 (Number of tracks per cylinder
                - Number of overflow tracks per cylinder) + 1)
                  (Number of bytes per index)

5. How many tracks on each cylinder can you use for prime data records?

      Prime data  = Tracks per cylinder
      tracks per  - Overflow tracks per cylinder
                  - Index tracks per cylinder

6. How many cylinders do you need for the prime data area?

   Number of cylinders = Prime data tracks / Prime data tracks per cylinder

7. How many tracks do you need for the cylinder index?

   Number of tracks required = (Track indexes + 1) / Index entries per track
   for cylinder index

8. How many tracks do you need for master indexes?

      Number of tracks required = (Number of cylinder index tracks + 1)
      for master indexes        / Index entries per track