Kakuro
Free cross-sum puzzles: make every run add up to its clue, with no repeated digits.
Fill every white cell with 1–9. Each run must add up to its clue, with no repeats.
Combination helper
How to read the clues
The top-right clue adds across →. The bottom-left clue adds down ↓. Use 1–9 with no repeats in a run.
N notes · 1–9 enter · arrows move.
See a worked example →Progress saved on this device. Take your time.
Kakuro is a number crossword: fill the white cells with 1–9 so each run adds up to its clue, and no digit repeats within a run. Select a cell to see which combinations fit.
Kakuro at a glance
- Also known as
- Cross Sums.
- Goal
- Fill white cells with 1–9 so each across and down run adds up to its clue.
- Key rule
- No digit repeats within a run.
- Math needed
- Only addition. Most of the work is knowing which digit sets make each sum.
- Grid sizes
- 4×4 to 8×8 playing area.
- Levels
- 30, each with exactly one solution.
- Cost
- Free in any browser. No sign-up.
Level guide
| Levels | Grid | Difficulty |
|---|---|---|
| 1–6 | 4×4 | Easy |
| 7–14 | 5×5 | Easy |
| 15–22 | 6×6 | Medium |
| 23–27 | 7×7 | Hard |
| 28–30 | 8×8 | Hard |
Learn the rules with an example and the combinations worth memorising. Prefer no arithmetic? Try Cat Sudoku or classic Sudoku.
Frequently asked questions
What is Kakuro?
Kakuro is a number crossword. Fill each white cell with a digit from 1 to 9 so that every horizontal and vertical run adds up to the clue printed at its start, without repeating a digit within a run.
Is Kakuro harder than Sudoku?
Kakuro adds simple addition, so it feels different rather than strictly harder. Small Kakuro grids are a gentle start, while large grids rival hard Sudoku. Knowing the common digit combinations makes it much faster.
What do the two numbers in a black cell mean?
The number in the top-right is the clue for the run of white cells to its right (across). The number in the bottom-left is the clue for the run below it (down).
Can a digit repeat in Kakuro?
Not within the same run. The same digit can appear elsewhere on the board, just not twice in one across or down run.
Are these Kakuro puzzles free?
Yes. All 30 Kakuro levels on Puzzdoku are free, play in your browser, and each has exactly one solution.