How to Play Kakurasu
Shade cells in a grid. Each row and column has a target sum, and the value of a shaded cell equals its column (or row) position number.
Try it now — Easy 7x7 →The Rules
- Shade cells so that each row and column meets its target sum
- A shaded cell's value equals its column position (column 1 = value 1, column 2 = value 2, etc.)
- For column sums, a shaded cell's value equals its row position
- Each cell is either shaded or unshaded — no digit is written in the cells
Available in 3 sizes (5x5, 7x7, 9x9) and 3 difficulty levels (easy, normal, hard).
See It in Action
Shade cells so each row and column sum matches its clue — a cell's value equals its column position
How to Play
- Identify unique subsets of available column positions that sum to each row's target
- Find rows where the target forces only one valid combination of positions
- Use column constraints to eliminate options: a column's target restricts which rows can shade it
- Cross-reference row and column constraints until every cell is determined
Pro Tips
Think like Kakuro: list all unique subsets of {1, 2, 3...} that sum to the target
If the target equals the sum of all column positions, every cell in that row must be shaded
Start with the most constrained rows or columns — those where only one combination is possible
Frequently Asked Questions
What is Kakurasu?
Kakurasu is a grid puzzle where you shade cells. The value of a shaded cell equals its position (column 1 = 1, column 2 = 2, etc.). Each row and column has a target sum that your shaded cells must match.
Choose Your Challenge
Start with easy to learn the rules, then progress to harder difficulties.