Online Calcudoku Puzzles

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How to

Calcudoku

Early 2009, I read about KenKen (also known as Calcudoku) in the New York Times, and decided to write a program that creates similar puzzles, and put them online. Calcudoku puzzles are similar to Sudoku, but also require some basic math skills to solve.

The rules are:

the 4×4 puzzle uses the numbers 1-4, the 6×6 the numbers 1-6, and so on
in each row and in each column each digit can appear only once (just like in Sudoku)
each "cage" (groups of cells with a thick border) shows a result and an operation (+ - × or :)
The operation applied to the numbers in the cage should produce the result shown.
Note that for subtraction and division the order is not fixed (!)

Check out this video that shows how to solve two example puzzles.

You can solve the puzzle on the page using the arrow and number keys, or using the mouse.
Other keys:

space bar : clear a cell
backspace : undo a move
= : highlight a number
Shift + number : enter the number as a guess

In the largest puzzles (10x10 Calcudoku puzzle (every Tuesday and Friday) and 12x12 (every Sunday and Thursday)), simply press 1 then 0, or 1 then 1, or 1 then 2 to enter 10, or 11, or 12. You can also use the a, b, and c keys to enter 10, 11, or 12.

You can also solve the puzzles on the iPhone/iPod Touch/iPad.

Every puzzle has a single solution.

This type of puzzle is known as Calcudoku, Newdoku, Rekendoku, MathDoku, Kashikoku-Naru, KenKen, Kendoku, Sumdoku, Calkuro, K-Doku, Keen, NekNek, CanCan, Square Wisdom, Emono, Minuplu, LatinCalc, Yukendo, ArithmeGrid, Hitoshii, Inky, SquareLogic, TomTom, and if you know of any other names, let me know :-). The "no-op" puzzles are sometimes called "Mystery Calcudoku". Of these names, "KenKen" and "KenDoku" are trademarks of Nextoy LLC. Note that this is a hobby site, and is not affiliated with Nextoy nor their brands.

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Today

Solution 2 Feb 2026

Easy:

4×4

5×5

6×6

Killer

Sudoku

Medium:

4×4

6×6

7×7

Sudoku

Difficult:

4×4

5×5

6×6

7×7

9×9

Extra

Difficult 5 × 5, Rating: ★★ Solved 257 times

Today this puzzle is for subscribers only
(5 × 5, Difficult)

→ New: you can unlock this puzzle by watching a video ad:

0×

0 :

0×

-1+

-4×

Note: in this puzzle, use the numbers from -2 to 2 instead of 1-5 !
To enter a negative number, first press the number, then the - key. To enter a negative guess, press Ctrl + the number
(so Ctrl+2 to enter -2 as a guess, for example)(use Shift + number for positive number guesses)

total

All puzzles published on this site are © Patrick Min. Send your ideas and suggestions to .

Tomorrow's puzzles will appear in hour(s) and minute(s).Order puzzles

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