Sudoku with arithmetic cages for solvers who want a harder hybrid challenge.
Puzzle explainer
What Is Killer Sudoku?
Killer Sudoku is a hybrid logic puzzle that combines the row, column, and box rules of Sudoku with arithmetic clues inside dotted cages.
Each cage has a small sum clue, and the digits inside that cage must add up to that total without repeating.
The result feels like Sudoku with an extra layer of number relationships and deduction.
Core facts
- Puzzle type: Sudoku variant with arithmetic cages.
- Also called: Sum Sudoku.
- Every row, column, and 3x3 box still contains the digits 1 through 9.
- Digits may not repeat inside a cage.
How Killer Sudoku differs from classic Sudoku
A regular Sudoku gives you some starting digits. Killer Sudoku usually gives you cage boundaries and sum clues instead. You still use standard Sudoku logic, but you also use arithmetic combinations to narrow down what can fit in each cage.
That means a cage total like 3 in two cells must be 1 and 2, while a larger cage can often be analyzed through candidate sets and elimination.
Why solvers enjoy it
- It blends familiar Sudoku structure with fresh deduction patterns.
- The cages create strong early constraints, even when the grid starts empty.
- It rewards both logical scanning and number-pattern recognition.
- Difficulty ranges from approachable intermediate books to extremely hard challenges.
Where to go next
Printable Killer Sudoku books
Browse printable books by difficulty, including 1-per-page and 4-per-page options.
Interactive Killer Sudoku
Try the online version if you want to solve without printing first.
Printable puzzle overview
Compare Killer Sudoku with other printable number and logic puzzle formats.
Related number puzzles
Classic printable Sudoku in multiple grid sizes and difficulty levels.
Cross-sums puzzles that combine arithmetic with crossword-style deduction.
Calcudoku-style puzzles with arithmetic clues and small, approachable grids.
Irregular-region Sudoku books that add a fresh spatial twist to the familiar rules.