The following tables list the possible combinations for various sums for Killer Sudoku 9x9.
I have also bundled all the Killer Sudoku cage total tables in a handy reference guide "Killer Sudoku - Cage Total Tables".
  The book lists the cage total tables for Killer Sudoku 6x6, 8x8, 9x9, 10x10 and 12x12.
  | 6:  | 1,2,3 | 
  | 7:  | 1,2,4 | 
  | 8:  | 1,2,5 1,3,4 | 
  | 9:  | 1,2,6 1,3,5 2,3,4 | 
  | 10:  | 1,2,7 1,3,6 1,4,5 2,3,5 | 
  | 11:  | 1,2,8 1,3,7 1,4,6 2,3,6 2,4,5 | 
  | 12:  | 1,2,9 1,3,8 1,4,7 1,5,6 2,3,7 2,4,6 3,4,5 | 
  | 13:  | 1,3,9 1,4,8 1,5,7 2,3,8 2,4,7 2,5,6 3,4,6 | 
  | 14:  | 1,4,9 1,5,8 1,6,7 2,3,9 2,4,8 2,5,7 3,4,7 3,5,6 | 
  | 15:  | 1,5,9 1,6,8 2,4,9 2,5,8 2,6,7 3,4,8 3,5,7 4,5,6 | 
  | 16:  | 1,6,9 1,7,8 2,5,9 2,6,8 3,4,9 3,5,8 3,6,7 4,5,7 | 
  | 17:  | 1,7,9 2,6,9 2,7,8 3,5,9 3,6,8 4,5,8 4,6,7 | 
  | 18:  | 1,8,9 2,7,9 3,6,9 3,7,8 4,5,9 4,6,8 5,6,7 | 
  | 19:  | 2,8,9 3,7,9 4,6,9 4,7,8 5,6,8 | 
  | 20:  | 3,8,9 4,7,9 5,6,9 5,7,8 | 
  | 21:  | 4,8,9 5,7,9 6,7,8 | 
  | 22:  | 5,8,9 6,7,9 | 
  | 23:  | 6,8,9 | 
  | 24:  | 7,8,9 | 
  | 10:  | 1,2,3,4 | 
  | 11:  | 1,2,3,5 | 
  | 12:  | 1,2,3,6 1,2,4,5 | 
  | 13:  | 1,2,3,7 1,2,4,6 1,3,4,5 | 
  | 14:  | 1,2,3,8 1,2,4,7 1,2,5,6 1,3,4,6 2,3,4,5 | 
  | 15:  | 1,2,3,9 1,2,4,8 1,2,5,7 1,3,4,7 1,3,5,6 2,3,4,6 | 
  | 16:  | 1,2,4,9 1,2,5,8 1,2,6,7 1,3,4,8 1,3,5,7 1,4,5,6
  2,3,4,7 2,3,5,6 | 
  | 17:  | 1,2,5,9 1,2,6,8 1,3,4,9 1,3,5,8 1,3,6,7 1,4,5,7
  2,3,4,8 2,3,5,7 2,4,5,6 | 
  | 18:  | 1,2,6,9 1,2,7,8 1,3,5,9 1,3,6,8 1,4,5,8 1,4,6,7
  2,3,4,9 2,3,5,8 2,3,6,7 2,4,5,7 3,4,5,6 | 
  | 19:  | 1,2,7,9 1,3,6,9 1,3,7,8 1,4,5,9 1,4,6,8 1,5,6,7
  2,3,5,9 2,3,6,8 2,4,5,8 2,4,6,7 3,4,5,7 | 
  | 20:  | 1,2,8,9 1,3,7,9 1,4,6,9 1,4,7,8 1,5,6,8 2,3,6,9
  2,3,7,8 2,4,5,9 2,4,6,8 2,5,6,7 3,4,5,8 3,4,6,7 | 
  | 21:  | 1,3,8,9 1,4,7,9 1,5,6,9 1,5,7,8 2,3,7,9 2,4,6,9
  2,4,7,8 2,5,6,8 3,4,5,9 3,4,6,8 3,5,6,7 | 
  | 22:  | 1,4,8,9 1,5,7,9 1,6,7,8 2,3,8,9 2,4,7,9 2,5,6,9
  2,5,7,8 3,4,6,9 3,4,7,8 3,5,6,8 4,5,6,7 | 
  | 23:  | 1,5,8,9 1,6,7,9 2,4,8,9 2,5,7,9 2,6,7,8 3,4,7,9
  3,5,6,9 3,5,7,8 4,5,6,8 | 
  | 24:  | 1,6,8,9 2,5,8,9 2,6,7,9 3,4,8,9 3,5,7,9 3,6,7,8
  4,5,6,9 4,5,7,8 | 
  | 25:  | 1,7,8,9 2,6,8,9 3,5,8,9 3,6,7,9 4,5,7,9 4,6,7,8 | 
  | 26:  | 2,7,8,9 3,6,8,9 4,5,8,9 4,6,7,9 5,6,7,8 | 
  | 27:  | 3,7,8,9 4,6,8,9 5,6,7,9 | 
  | 28:  | 4,7,8,9 5,6,8,9 | 
  | 29:  | 5,7,8,9 | 
  | 30:  | 6,7,8,9 | 
  | 15:  | 1,2,3,4,5 | 
  | 16:  | 1,2,3,4,6 | 
  | 17:  | 1,2,3,4,7 1,2,3,5,6 | 
  | 18:  | 1,2,3,4,8 1,2,3,5,7 1,2,4,5,6 | 
  | 19:  | 1,2,3,4,9 1,2,3,5,8 1,2,3,6,7 1,2,4,5,7 1,3,4,5,6 | 
  | 20:  | 1,2,3,5,9 1,2,3,6,8 1,2,4,5,8 1,2,4,6,7 1,3,4,5,7
  2,3,4,5,6 | 
  | 21:  | 1,2,3,6,9 1,2,3,7,8 1,2,4,5,9 1,2,4,6,8 1,2,5,6,7
  1,3,4,5,8 1,3,4,6,7 2,3,4,5,7 | 
  | 22:  | 1,2,3,7,9 1,2,4,6,9 1,2,4,7,8 1,2,5,6,8 1,3,4,5,9
  1,3,4,6,8 1,3,5,6,7 2,3,4,5,8 2,3,4,6,7 | 
  | 23:  | 1,2,3,8,9 1,2,4,7,9 1,2,5,6,9 1,2,5,7,8 1,3,4,6,9
  1,3,4,7,8 1,3,5,6,8 1,4,5,6,7 2,3,4,5,9 2,3,4,6,8
  2,3,5,6,7 | 
  | 24:  | 1,2,4,8,9 1,2,5,7,9 1,2,6,7,8 1,3,4,7,9 1,3,5,6,9
  1,3,5,7,8 1,4,5,6,8 2,3,4,6,9 2,3,4,7,8 2,3,5,6,8
  2,4,5,6,7 | 
  | 25:  | 1,2,5,8,9 1,2,6,7,9 1,3,4,8,9 1,3,5,7,9 1,3,6,7,8
  1,4,5,6,9 1,4,5,7,8 2,3,4,7,9 2,3,5,6,9 2,3,5,7,8
  2,4,5,6,8 3,4,5,6,7 | 
  | 26:  | 1,2,6,8,9 1,3,5,8,9 1,3,6,7,9 1,4,5,7,9 1,4,6,7,8
  2,3,4,8,9 2,3,5,7,9 2,3,6,7,8 2,4,5,6,9 2,4,5,7,8
  3,4,5,6,8 | 
  | 27:  | 1,2,7,8,9 1,3,6,8,9 1,4,5,8,9 1,4,6,7,9 1,5,6,7,8
  2,3,5,8,9 2,3,6,7,9 2,4,5,7,9 2,4,6,7,8 3,4,5,6,9
  3,4,5,7,8 | 
  | 28:  | 1,3,7,8,9 1,4,6,8,9 1,5,6,7,9 2,3,6,8,9 2,4,5,8,9
  2,4,6,7,9 2,5,6,7,8 3,4,5,7,9 3,4,6,7,8 | 
  | 29:  | 1,4,7,8,9 1,5,6,8,9 2,3,7,8,9 2,4,6,8,9 2,5,6,7,9
  3,4,5,8,9 3,4,6,7,9 3,5,6,7,8 | 
  | 30:  | 1,5,7,8,9 2,4,7,8,9 2,5,6,8,9 3,4,6,8,9 3,5,6,7,9
  4,5,6,7,8 | 
  | 31:  | 1,6,7,8,9 2,5,7,8,9 3,4,7,8,9 3,5,6,8,9 4,5,6,7,9 | 
  | 32:  | 2,6,7,8,9 3,5,7,8,9 4,5,6,8,9 | 
  | 33:  | 3,6,7,8,9 4,5,7,8,9 | 
  | 34:  | 4,6,7,8,9 | 
  | 35:  | 5,6,7,8,9 | 
  | 21:  | 1,2,3,4,5,6 | 
  | 22:  | 1,2,3,4,5,7 | 
  | 23:  | 1,2,3,4,5,8 1,2,3,4,6,7 | 
  | 24:  | 1,2,3,4,5,9 1,2,3,4,6,8 1,2,3,5,6,7 | 
  | 25:  | 1,2,3,4,6,9 1,2,3,4,7,8 1,2,3,5,6,8 1,2,4,5,6,7 | 
  | 26:  | 1,2,3,4,7,9 1,2,3,5,6,9 1,2,3,5,7,8 1,2,4,5,6,8
  1,3,4,5,6,7 | 
  | 27:  | 1,2,3,4,8,9 1,2,3,5,7,9 1,2,3,6,7,8 1,2,4,5,6,9
  1,2,4,5,7,8 1,3,4,5,6,8 2,3,4,5,6,7 | 
  | 28:  | 1,2,3,5,8,9 1,2,3,6,7,9 1,2,4,5,7,9 1,2,4,6,7,8
  1,3,4,5,6,9 1,3,4,5,7,8 2,3,4,5,6,8 | 
  | 29:  | 1,2,3,6,8,9 1,2,4,5,8,9 1,2,4,6,7,9 1,2,5,6,7,8
  1,3,4,5,7,9 1,3,4,6,7,8 2,3,4,5,6,9 2,3,4,5,7,8 | 
  | 30:  | 1,2,3,7,8,9 1,2,4,6,8,9 1,2,5,6,7,9 1,3,4,5,8,9
  1,3,4,6,7,9 1,3,5,6,7,8 2,3,4,5,7,9 2,3,4,6,7,8 | 
  | 31:  | 1,2,4,7,8,9 1,2,5,6,8,9 1,3,4,6,8,9 1,3,5,6,7,9
  1,4,5,6,7,8 2,3,4,5,8,9 2,3,4,6,7,9 2,3,5,6,7,8 | 
  | 32:  | 1,2,5,7,8,9 1,3,4,7,8,9 1,3,5,6,8,9 1,4,5,6,7,9
  2,3,4,6,8,9 2,3,5,6,7,9 2,4,5,6,7,8 | 
  | 33:  | 1,2,6,7,8,9 1,3,5,7,8,9 1,4,5,6,8,9 2,3,4,7,8,9
  2,3,5,6,8,9 2,4,5,6,7,9 3,4,5,6,7,8 | 
  | 34:  | 1,3,6,7,8,9 1,4,5,7,8,9 2,3,5,7,8,9 2,4,5,6,8,9
  3,4,5,6,7,9 | 
  | 35:  | 1,4,6,7,8,9 2,3,6,7,8,9 2,4,5,7,8,9 3,4,5,6,8,9 | 
  | 36:  | 1,5,6,7,8,9 2,4,6,7,8,9 3,4,5,7,8,9 | 
  | 37:  | 2,5,6,7,8,9 3,4,6,7,8,9 | 
  | 38:  | 3,5,6,7,8,9 | 
  | 39:  | 4,5,6,7,8,9 | 
  | 28:  | 1,2,3,4,5,6,7 | 
  | 29:  | 1,2,3,4,5,6,8 | 
  | 30:  | 1,2,3,4,5,6,9 1,2,3,4,5,7,8 | 
  | 31:  | 1,2,3,4,5,7,9 1,2,3,4,6,7,8 | 
  | 32:  | 1,2,3,4,5,8,9 1,2,3,4,6,7,9 1,2,3,5,6,7,8 | 
  | 33:  | 1,2,3,4,6,8,9 1,2,3,5,6,7,9 1,2,4,5,6,7,8 | 
  | 34:  | 1,2,3,4,7,8,9 1,2,3,5,6,8,9 1,2,4,5,6,7,9
  1,3,4,5,6,7,8 | 
  | 35:  | 1,2,3,5,7,8,9 1,2,4,5,6,8,9 1,3,4,5,6,7,9
  2,3,4,5,6,7,8 | 
  | 36:  | 1,2,3,6,7,8,9 1,2,4,5,7,8,9 1,3,4,5,6,8,9
  2,3,4,5,6,7,9 | 
  | 37:  | 1,2,4,6,7,8,9 1,3,4,5,7,8,9 2,3,4,5,6,8,9 | 
  | 38:  | 1,2,5,6,7,8,9 1,3,4,6,7,8,9 2,3,4,5,7,8,9 | 
  | 39:  | 1,3,5,6,7,8,9 2,3,4,6,7,8,9 | 
  | 40:  | 1,4,5,6,7,8,9 2,3,5,6,7,8,9 | 
  | 41:  | 2,4,5,6,7,8,9 | 
  | 42:  | 3,4,5,6,7,8,9 |