Sudoku and Calcudoku are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Calcudoku is very close to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: n×n (commonly 4×4–9×9)
- Closeness to Sudoku: Very Close
- Also called: KenKen, Mathdoku, Kendoku
What is Calcudoku?
A Latin-square grid divided into cages, each printed with a target and an operation the cage's numbers must produce. Here are the rules in full:
- Fill an n×n grid so each row and column holds 1–n exactly once.
- Cages carry a target and an operation (+, −, ×, ÷); the cage's numbers must produce that target.
- A number may repeat inside a cage, as long as it doesn't break the row/column rule.
See a Calcudoku cage
Calcudoku (also sold as KenKen) is a Latin square split into cages, each printed with a target and an operation. Here a two-cell cage marked "6×" holds 2 and 3, since 2 × 3 = 6.
A Calcudoku board: each coloured cage carries a target and an operation. Fill 1–4 in every row and column so each cage's digits hit its target — a "6×" cage, for instance, holds 2 and 3.
Swap the boxes for arithmetic cages and you have Killer Sudoku with all four operations — very close to Killer Sudoku Pro. The Latin-square rule is Sudoku's core, and the "which digits make this target?" reasoning is exactly Killer's combination logic, extended from sums to products and quotients.
What Calcudoku shares with Sudoku
- The Latin-square rule — each number once per row and column — is Sudoku's core.
- Cages with arithmetic targets are the idea behind Killer and XV Sudoku.
- Combination analysis — listing which numbers hit a target — drives both.
How Calcudoku differs from Sudoku
- It uses subtraction, multiplication and division, not just addition.
- A number can repeat within a cage, which Killer cages forbid.
- There are no boxes, and the grid is often smaller than 9×9.
Do Sudoku skills transfer?
The cage-combination skill from Killer Sudoku transfers directly — you just extend it from sums to products and quotients. A "×12 in two cells" cage is the same kind of "which pairs make this?" reasoning as a Killer sum.
Brush up on the technique that carries over: Killer Combinations.
The verdict
Calcudoku (KenKen) is Killer Sudoku with the full four operations and no boxes — arithmetic cages on a Latin square.
Prefer to stay with Sudoku?
If Calcudoku appeals, these Sudoku variants scratch the same itch and you can read up on each here: