Calcudoku: today's grid is ready
Fill the grid so every row and column uses each number once. Each outlined cage must make its target with the operation shown. Everyone gets the same daily puzzle; a new one appears at midnight.
How to solve Calcudoku
Start with single-cell cages: their number is given. Then look at two-cell cages with division or a large product, since they allow only a few pairs. Use the row and column rule to eliminate options, the same way you would in Sudoku. In a 5×5 grid, every row adds up to 15.
Sumthread is a calm number-path puzzle for iPhone: trace one path through every tile and hit the target sums in order. Five thoughtful minutes at a time.
Free on the App StoreQuestions
What is Calcudoku?
A logic puzzle that mixes Sudoku-style rows and columns with arithmetic. Each row and column contains every number from 1 to the grid size once, and each cage must produce its target using its operation.
Do the numbers in a cage have to be different?
Only within a row or column. A cage that bends across rows can repeat a number, as long as the repeats are not in the same row or column.
Is there a new puzzle every day?
Yes. The daily puzzle is the same for everyone and changes at midnight in your time zone. You can also generate unlimited random puzzles.
Can I print puzzles?
Yes. Press Print to get a clean blank grid with cage targets, ready for paper.
Is there an app with puzzles like this?
Sumthread, our iPhone puzzle game, is a calm number-path puzzle: trace one path through every tile and hit the target sums in order.
- Daily number path puzzleTrace one thread from 1 to the last number through every square, passing each given number in order. A new free puzzle every day, in three sizes.
- Flow Free alternativeLove Flow Free's fill-the-board puzzles? Sumthread is a calm number-path puzzle where one thread covers every tile, fully offline, with no ads and no account.
- Open the Kakuro combinations calculatorFree Kakuro combinations calculator: choose the clue sum and number of cells to see every possible set of digits 1–9, which digits must appear, unique sets, and a full reference table.