Kakuro is often called the mathematical cousin of crosswords — a number puzzle where you fill cells with digits 1-9 so that each group sums to a specific target. It combines the logical deduction of Sudoku with arithmetic, creating a deeply satisfying puzzle experience. Play Kakuro online free with our collection of hand-crafted puzzles. Each clue cell shows one or two target sums — one for the group running across, one for the group running down. Fill in the white cells with digits 1-9 such that each group sums to its target and no digit repeats within a group. Kakuro rewards careful logic and knowledge of number combinations. Once you learn which digits can make common sums, you'll start solving clues instantly. It's a wonderful daily brain exercise for anyone who loves numbers and logic puzzles.
How to Play Kakuro
The grid contains clue cells (with diagonal splits showing target numbers) and empty cells to fill. Each clue number is the target sum for the consecutive white cells running to its right (across) or below (down).
Click an empty cell and type a digit 1-9 to fill it. Each group of consecutive cells must sum to exactly the target number, and no digit can repeat within the same group. Use these two constraints together to narrow down possibilities.
Start with small groups — a 2-cell group with sum 3 must be {1,2}, and a 2-cell group with sum 17 must be {8,9}. Cross-reference intersecting groups to eliminate candidates. The key insight is that many sums have very few possible combinations.
Kakuro Tips & Strategies
- Memorize key combinations: sum 3 in 2 cells = {1,2}, sum 4 in 2 cells = {1,3}, sum 16 in 2 cells = {7,9}.
- Start with the smallest and largest sums — they have the fewest possible combinations.
- Cross-reference intersecting groups to narrow candidates in shared cells.
- A sum of 45 in 9 cells means every digit 1-9 appears exactly once.
- Look for groups where only one arrangement works given the constraints from intersecting groups.
- Never guess — every cell can be determined through logical deduction.
Frequently Asked Questions
How is Kakuro different from Sudoku?
Kakuro involves arithmetic — you must make groups of cells sum to target numbers. Like Sudoku, digits can't repeat within a group, but Kakuro groups vary in size and have specific sum targets. It's like a number crossword.
What digits can I use in Kakuro?
Only the digits 1 through 9. Zero is never used. No digit can repeat within the same horizontal or vertical group, but the same digit can appear in different groups.
What are the most useful Kakuro combinations to memorize?
Key combos: 2 cells summing to 3 = {1,2}, to 4 = {1,3}, to 16 = {7,9}, to 17 = {8,9}. For 3 cells: sum 6 = {1,2,3}, sum 24 = {7,8,9}. These constrained combinations are your best starting points.
