How to Play Kakuro
Fill the white cells with digits 1–9 so that the sums of each across and down run match the clue numbers, without repeating digits in any run.
Try it now — Easy 8x8 →The Rules
- Fill white cells with digits 1–9
- Each horizontal or vertical "run" must sum to the clue shown in the black cell adjacent to it
- No digit may repeat within a single run
- Every white cell must have a value — no blank cells in the final solution
Available in 3 sizes (5x5, 8x8, 10x10) and 3 difficulty levels (easy, normal, hard).
See It in Action
Fill digits 1–9 so each run sums to its clue — no repeating digits within a run
How to Play
- Find short runs (2–3 cells) with extreme sums — a 2-cell run summing to 3 must be 1+2; to 17 must be 8+9
- List all valid digit combinations for each run, then eliminate based on cross-run intersections
- Cells at the intersection of two constrained runs must satisfy both — these are determined first
- Eliminate candidates until each cell has exactly one valid digit
Pro Tips
Memorize unique combinations: 3 in 2 cells = {1,2}; 4 in 2 = {1,3}; 16 in 2 = {7,9}; 17 in 2 = {8,9}
Cells at run intersections are the most constrained — focus on those to break open the puzzle
A high clue with few cells means each digit must be large; a low clue with few cells means each must be small
Frequently Asked Questions
What is Kakuro?
Kakuro is a number crossword. Fill white cells with digits 1–9 so each horizontal and vertical "run" sums to its clue. Digits cannot repeat within a single run.
Choose Your Challenge
Start with easy to learn the rules, then progress to harder difficulties.