9x9 Killer Sudoku Puzzles

The 9x9 killer sudoku is the one you find in newspapers and puzzle books: eighty-one empty cells, the digits 1 to 9, and between thirty-five and forty cages whose sums are the only clues. The rules of sudoku still hold in every row, column and 3x3 box, and each cage adds a small sum to honour, without repeating a digit inside it.

These eight puzzles put one large grid on each page, with space to write candidates. Most cages hold two cells, a few hold three, and the single-cell cages give a digit away at the start; the rest is logic, from the cages with a single combination to the rule of 45 that every row, column and box obeys. Each puzzle has one solution, and none needs a guess.

Part of the Sudoku Puzzles collection, Last updated on Tue, 27 Oct 2026 17:45:53 GMT.

Free Printables

9x9 Killer Sudoku, Puzzle 1

9x9 killer sudoku with thirty-eight cages: two single cells (2 and 3), twenty-nine two-cell cages and seven of three cells, with sums from 2 to 24, that largest one holding 7, 8 and 9. Puzzle 1 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 2

9x9 killer sudoku with thirty-five cages, one of them a single cell of sum 6, twenty-two two-cell cages and twelve of three cells; sums from 4 (1 and 3) to 22. The many three-cell cages make it the slower grid of the set. Puzzle 2 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 3

9x9 killer sudoku with thirty-seven cages: three single cells (4, 7 and 9) to start from, twenty-four two-cell cages and ten of three cells, with sums from 4 to 21. Puzzle 3 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 4

9x9 killer sudoku with thirty-seven cages: two single cells (2 and 4), twenty-six two-cell cages and nine of three cells, with sums from 2 to 24, the 24 being 7, 8 and 9 in some order. Puzzle 4 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 5

9x9 killer sudoku with thirty-seven cages: two single cells (4 and 5), twenty-six two-cell cages and nine of three cells, with sums from 3, which can only be 1 and 2, to 23. Puzzle 5 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 6

9x9 killer sudoku with thirty-nine cages, four of them single cells (1, 4, 8 and 9) that give four digits at once, twenty-eight two-cell cages and seven of three cells; sums from 1 to 21. The gentlest grid of the set. Puzzle 6 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 7

9x9 killer sudoku with thirty-seven cages: four single cells (3, 4, 5 and 8), twenty-two two-cell cages and eleven of three cells, with sums from 3 to 23. Puzzle 7 of 8. | zuzuzi.com

9x9 Killer Sudoku, Puzzle 8

9x9 killer sudoku built almost entirely of pairs: twenty-nine two-cell cages, seven three-cell cages and two single cells (2 and 3), thirty-eight cages in all, with sums from 2 to 22. Puzzle 8 of 8. | zuzuzi.com

How to Solve a 9x9 Killer Sudoku

Begin with the cages that admit a single combination: a two-cell cage of sum 3 is 1 and 2, of sum 4 is 1 and 3, of sum 16 is 7 and 9, of sum 17 is 8 and 9; a three-cell cage of sum 6 is 1, 2 and 3, and one of sum 24 is 7, 8 and 9. Then use the rule of 45: every row, column and 3x3 box adds up to 45, so when the cages inside a box cover all but one cell, that cell is 45 minus their sums; the same trick works on a row, a column, or two boxes side by side, which add up to 90.

Keep candidates small and tidy, cross out what a placed digit forbids in its row, column, box and cage, and let each cage shrink to its last option. The grids of this set take from twenty minutes to an hour.

Frequently Asked Questions

How many cages does a 9x9 killer sudoku have?

In this set, between thirty-five and thirty-nine. Most hold two cells, some three, and a few are single cells, whose sum is simply the digit to write.

Why is the rule of 45 so useful?

Because every row, column and 3x3 box contains the digits 1 to 9 exactly once, and 1 to 9 add up to 45. When cages fill a box except for one cell, that cell is 45 minus the cage sums; when a cage sticks out of a box by one cell, that cell is the cage sums of the box minus 45. It is the fastest way into most grids.