Play Kakuro Online
Kakuro is the crossword of number puzzles: instead of words you enter digits, and instead of clues there are sums. Every horizontal and vertical run must add up to its given total, using nothing but distinct digits from 1 to 9. At Sudoku Sagax there are 800 levels, ad-free and with no sign-up required.
What is kakuro?
A kakuro grid consists of white entry squares and black clue squares. A clue square carries one or two small numbers separated by a diagonal: the number in the top right is the total for the run going right, the one in the bottom left the total for the run going down.
A run is an unbroken sequence of white squares. Its digits must add up to the stated total and may not repeat within that run. Only the digits 1 to 9 appear; there is no zero.
The puzzle is also known as cross sums. Unlike sudoku there really is arithmetic here — but only addition, and never beyond 45.
The rules, explained simply
Three rules will do:
- Only 1 to 9. Every white square takes a digit from 1 to 9. There is no zero.
- The sum must match. The digits of a run add up to exactly the number in the clue square before or above it.
- No repeats within a run. No digit appears twice in the same run. The same digit may of course reappear in a different run.
Every square belongs to two runs at once, one horizontal and one vertical. That overlap is precisely what makes the puzzle solvable.
Techniques: know your sums
Kakuro lives on the fact that some totals allow only one set of digits. Knowing those gives you instant footholds:
- The forced totals. Two squares totalling 3 are always 1+2; 4 is 1+3; 16 is 7+9; 17 is 8+9. Three squares totalling 6 are 1+2+3, and 24 is 7+8+9. These are free.
- Crossings first. Look for a square where two such forced runs cross. If one allows only 1 or 2 and the other only 2 or 9, the answer is a 2.
- Rule out the extremes. A run of two squares can total at most 17 (8+9) and at least 3 (1+2). Every run length has a minimum and a maximum like this — anything outside is impossible.
- Keep notes. Pencil the possible digits into the square. Each digit placed in the crossing run removes options, and the chains tend to resolve themselves.
Kakuro at Sudoku Sagax
You will find kakuro from the home screen under "All game types". There are 800 levels of its own, a separate leaderboard and a trophy for your first solved kakuro. Every level you finish counts towards your daily streak and the shared points pool.
Randomly generated kakuros are almost never unique, so every puzzle comes with a small number of given starting digits — just enough to leave exactly one solution. Each level is generated from its number and looks identical for everyone.
Notes, error highlighting, hints and undo work as they do in classic sudoku. Everything runs in the browser, ad-free, with no trackers and locally served fonts.
Frequently asked questions
What is kakuro?
Kakuro is a number puzzle laid out like a crossword. Instead of words you enter digits from 1 to 9. Every horizontal and vertical sequence of white squares must add up to the total given in the black clue square, and no digit may repeat within a sequence. It is also called cross sums.
How do you start a kakuro?
With the runs whose total allows only one set of digits: two squares totalling 3 are 1+2, 17 is 8+9, three squares totalling 6 are 1+2+3. Then look for crossings between two such runs — the digit there is usually determined immediately.
Can a digit repeat in kakuro?
Not within a run. The same digit may appear again in a different run — unlike sudoku there is no rule spanning whole rows or columns of the grid.
Do you need to be good at arithmetic?
Only at addition, and never beyond 45. Recognition matters more than calculation: which totals allow which digits for a given number of squares? You will have those combinations in your head after a few puzzles.