Free calcudoku puzzles, solver and printables

KenKen Solver

Draw the cages, type each target and operation, then solve the whole grid or one logical step at a time.

The KenKen solver is a free tool that finds the answer to a KenKen-style puzzle, also called a calcudoku, mathdoku or kendoku. You enter the grid and its cages, and the solver fills in the digits and tells you whether the puzzle has exactly one solution.

It runs in your web browser. There is no sign-up and nothing to install, and nothing is uploaded, because the puzzle is handled on your device. You can also use it as a study aid: the Next step button shows one logical move at a time, with the reason for it. KenKen is a registered trademark of Nextoy, LLC. This site is not affiliated with it, so we call our puzzles KenKen-style.

How to use the KenKen solver

  1. Choose a grid size from 3x3 to 9x9.
  2. Open the ‘Draw cages’ mode. Tap cells one at a time, or drag across them, to select a cage. The cells of one cage must touch by sides, not corners.
  3. Type the cage number (the target) in the number box.
  4. Pick the operation: +, −, ×, ÷, or = for a single cell. If you do not know the operation, pick ?.
  5. Press Add cage. Repeat until the status shows that every cell is covered.
  6. Check the ‘Cages entered’ list. Press Edit or Remove to fix a cage. You can also tap a finished cage to edit it.
  7. Press ‘Check it has one solution’. If the message says no solutions or more than one, a cage is probably missing or mistyped.
  8. Press Solve to fill the grid, or press Next step to go one move at a time. Press Next step again to apply each move and see the next one.

If you already have some digits, use the ‘Type digits you know’ mode. The solver uses them as clues. To load a puzzle made on this site, paste its code or link into ‘Paste a puzzle code or link’. Use the arrow keys to move, Space to add or remove a cell from the cage you are drawing, and Esc to clear the selection. Show candidates, Reveal one cell, Load an example and Start over are also available.

KenKen solver step by step

The solver works in stages. For each cage, it lists every set of digits that can produce the target with that operation. It then removes any set that would repeat a digit in a row or column, and searches what is left. The same search proves whether the answer is unique. For example, in a 4x4 grid a two-cell 3+ cage can only hold 1 and 2, and a 7+ cage can only hold 3 and 4.

The site rates difficulty by the steps needed, not by grid size. Easy puzzles need only single-cell cages, ‘only one digit fits’, ‘only one place for a digit’ and cage combinations. Medium adds pairs, or a digit forced onto a line by a cage. Hard needs a triple or one round of trial and error. Expert needs deeper trial and error.

KenKen puzzle with answer and explanation

Every row and column must contain each digit from 1 to n exactly once, where n is the grid size. Each cage’s digits, combined with its operation, must give its target. When you press Solve, the message says whether the answer is the only one, so you know the filled grid is the answer and not just one of several.

Cage combinations are where an explanation starts. In a 6x6 grid, a 1− cage can be 1-2, 2-3, 3-4, 4-5 or 5-6. In a 9x9 grid, a two-cell 17+ cage can only hold 8 and 9. Each step that Next step shows gives its reason, so you can see why a digit is placed.

Why does a KenKen puzzle have more than one solution?

A puzzle with more than one solution usually has a cage that is missing, has a wrong target, or has the wrong operation. The solver’s check will report this, and the cage list shows what you entered. Fix the cage with Edit, then run the check again.

Frequently asked questions

Is the KenKen solver free?

Yes. It is free, needs no account and solves the puzzle on your device.

How do I enter a puzzle with cages?

Choose the grid size, open ‘Draw cages’, select the cells of one cage, type the target, pick the operation and press Add cage. Repeat for every cage until the status shows all cells are covered.

What if I don’t know the operation of a cage?

Pick ? as the operation. The solver tries every operation that fits the cage. Subtraction and division are only tried for two-cell cages.

Why does it say more than one solution?

Usually a cage is missing or mistyped. Press ‘Check it has one solution’, then use Edit or Remove in the cage list to correct the cage.

Can the solver show the answer step by step?

Yes. Press Next step: it shows one logical step and the reason for it, and pressing again does that step and shows the next. When no simple step is left it says so, and Solve gives the rest.

Yes. Paste a code or link made on this site into ‘Paste a puzzle code or link’. Links are made with Copy link on the play pages.