Kakuro Combination Reference

Every valid set of distinct digits (1–9) for each run length and sum value. Rows highlighted in blue mark forced (unique) combinations — when only one combination exists, those digits must appear in the run regardless of cell order.

Use this table alongside the Sum Singles and Combination Pruning guides. If you want to filter a single clue interactively, open the Kakuro helper. Jump to a run length: 2· 3· 4· 5· 6· 7· 8· 9.

2-Cell Runs

Sum range: 3–17  ·  4 forced combinations

Sum Valid combinations Count
3 {1+2} 1
4 {1+3} 1
5 {1+4}{2+3} 2
6 {1+5}{2+4} 2
7 {1+6}{2+5}{3+4} 3
8 {1+7}{2+6}{3+5} 3
9 {1+8}{2+7}{3+6}{4+5} 4
10 {1+9}{2+8}{3+7}{4+6} 4
11 {2+9}{3+8}{4+7}{5+6} 4
12 {3+9}{4+8}{5+7} 3
13 {4+9}{5+8}{6+7} 3
14 {5+9}{6+8} 2
15 {6+9}{7+8} 2
16 {7+9} 1
17 {8+9} 1

3-Cell Runs

Sum range: 6–24  ·  4 forced combinations

Sum Valid combinations Count
6 {1+2+3} 1
7 {1+2+4} 1
8 {1+2+5}{1+3+4} 2
9 {1+2+6}{1+3+5}{2+3+4} 3
10 {1+2+7}{1+3+6}{1+4+5}{2+3+5} 4
11 {1+2+8}{1+3+7}{1+4+6}{2+3+6}{2+4+5} 5
12 {1+2+9}{1+3+8}{1+4+7}{1+5+6}{2+3+7}{2+4+6}{3+4+5} 7
13 {1+3+9}{1+4+8}{1+5+7}{2+3+8}{2+4+7}{2+5+6}{3+4+6} 7
14 {1+4+9}{1+5+8}{1+6+7}{2+3+9}{2+4+8}{2+5+7}{3+4+7}{3+5+6} 8
15 {1+5+9}{1+6+8}{2+4+9}{2+5+8}{2+6+7}{3+4+8}{3+5+7}{4+5+6} 8
16 {1+6+9}{1+7+8}{2+5+9}{2+6+8}{3+4+9}{3+5+8}{3+6+7}{4+5+7} 8
17 {1+7+9}{2+6+9}{2+7+8}{3+5+9}{3+6+8}{4+5+8}{4+6+7} 7
18 {1+8+9}{2+7+9}{3+6+9}{3+7+8}{4+5+9}{4+6+8}{5+6+7} 7
19 {2+8+9}{3+7+9}{4+6+9}{4+7+8}{5+6+8} 5
20 {3+8+9}{4+7+9}{5+6+9}{5+7+8} 4
21 {4+8+9}{5+7+9}{6+7+8} 3
22 {5+8+9}{6+7+9} 2
23 {6+8+9} 1
24 {7+8+9} 1

4-Cell Runs

Sum range: 10–30  ·  4 forced combinations

Sum Valid combinations Count
10 {1+2+3+4} 1
11 {1+2+3+5} 1
12 {1+2+3+6}{1+2+4+5} 2
13 {1+2+3+7}{1+2+4+6}{1+3+4+5} 3
14 {1+2+3+8}{1+2+4+7}{1+2+5+6}{1+3+4+6}{2+3+4+5} 5
15 {1+2+3+9}{1+2+4+8}{1+2+5+7}{1+3+4+7}{1+3+5+6}{2+3+4+6} 6
16 {1+2+4+9}{1+2+5+8}{1+2+6+7}{1+3+4+8}{1+3+5+7}{1+4+5+6}{2+3+4+7}{2+3+5+6} 8
17 {1+2+5+9}{1+2+6+8}{1+3+4+9}{1+3+5+8}{1+3+6+7}{1+4+5+7}{2+3+4+8}{2+3+5+7}{2+4+5+6} 9
18 {1+2+6+9}{1+2+7+8}{1+3+5+9}{1+3+6+8}{1+4+5+8}{1+4+6+7}{2+3+4+9}{2+3+5+8}{2+3+6+7}{2+4+5+7}{3+4+5+6} 11
19 {1+2+7+9}{1+3+6+9}{1+3+7+8}{1+4+5+9}{1+4+6+8}{1+5+6+7}{2+3+5+9}{2+3+6+8}{2+4+5+8}{2+4+6+7}{3+4+5+7} 11
20 {1+2+8+9}{1+3+7+9}{1+4+6+9}{1+4+7+8}{1+5+6+8}{2+3+6+9}{2+3+7+8}{2+4+5+9}{2+4+6+8}{2+5+6+7}{3+4+5+8}{3+4+6+7} 12
21 {1+3+8+9}{1+4+7+9}{1+5+6+9}{1+5+7+8}{2+3+7+9}{2+4+6+9}{2+4+7+8}{2+5+6+8}{3+4+5+9}{3+4+6+8}{3+5+6+7} 11
22 {1+4+8+9}{1+5+7+9}{1+6+7+8}{2+3+8+9}{2+4+7+9}{2+5+6+9}{2+5+7+8}{3+4+6+9}{3+4+7+8}{3+5+6+8}{4+5+6+7} 11
23 {1+5+8+9}{1+6+7+9}{2+4+8+9}{2+5+7+9}{2+6+7+8}{3+4+7+9}{3+5+6+9}{3+5+7+8}{4+5+6+8} 9
24 {1+6+8+9}{2+5+8+9}{2+6+7+9}{3+4+8+9}{3+5+7+9}{3+6+7+8}{4+5+6+9}{4+5+7+8} 8
25 {1+7+8+9}{2+6+8+9}{3+5+8+9}{3+6+7+9}{4+5+7+9}{4+6+7+8} 6
26 {2+7+8+9}{3+6+8+9}{4+5+8+9}{4+6+7+9}{5+6+7+8} 5
27 {3+7+8+9}{4+6+8+9}{5+6+7+9} 3
28 {4+7+8+9}{5+6+8+9} 2
29 {5+7+8+9} 1
30 {6+7+8+9} 1

5-Cell Runs

Sum range: 15–35  ·  4 forced combinations

Sum Valid combinations Count
15 {1+2+3+4+5} 1
16 {1+2+3+4+6} 1
17 {1+2+3+4+7}{1+2+3+5+6} 2
18 {1+2+3+4+8}{1+2+3+5+7}{1+2+4+5+6} 3
19 {1+2+3+4+9}{1+2+3+5+8}{1+2+3+6+7}{1+2+4+5+7}{1+3+4+5+6} 5
20 {1+2+3+5+9}{1+2+3+6+8}{1+2+4+5+8}{1+2+4+6+7}{1+3+4+5+7}{2+3+4+5+6} 6
21 {1+2+3+6+9}{1+2+3+7+8}{1+2+4+5+9}{1+2+4+6+8}{1+2+5+6+7}{1+3+4+5+8}{1+3+4+6+7}{2+3+4+5+7} 8
22 {1+2+3+7+9}{1+2+4+6+9}{1+2+4+7+8}{1+2+5+6+8}{1+3+4+5+9}{1+3+4+6+8}{1+3+5+6+7}{2+3+4+5+8}{2+3+4+6+7} 9
23 {1+2+3+8+9}{1+2+4+7+9}{1+2+5+6+9}{1+2+5+7+8}{1+3+4+6+9}{1+3+4+7+8}{1+3+5+6+8}{1+4+5+6+7}{2+3+4+5+9}{2+3+4+6+8}{2+3+5+6+7} 11
24 {1+2+4+8+9}{1+2+5+7+9}{1+2+6+7+8}{1+3+4+7+9}{1+3+5+6+9}{1+3+5+7+8}{1+4+5+6+8}{2+3+4+6+9}{2+3+4+7+8}{2+3+5+6+8}{2+4+5+6+7} 11
25 {1+2+5+8+9}{1+2+6+7+9}{1+3+4+8+9}{1+3+5+7+9}{1+3+6+7+8}{1+4+5+6+9}{1+4+5+7+8}{2+3+4+7+9}{2+3+5+6+9}{2+3+5+7+8}{2+4+5+6+8}{3+4+5+6+7} 12
26 {1+2+6+8+9}{1+3+5+8+9}{1+3+6+7+9}{1+4+5+7+9}{1+4+6+7+8}{2+3+4+8+9}{2+3+5+7+9}{2+3+6+7+8}{2+4+5+6+9}{2+4+5+7+8}{3+4+5+6+8} 11
27 {1+2+7+8+9}{1+3+6+8+9}{1+4+5+8+9}{1+4+6+7+9}{1+5+6+7+8}{2+3+5+8+9}{2+3+6+7+9}{2+4+5+7+9}{2+4+6+7+8}{3+4+5+6+9}{3+4+5+7+8} 11
28 {1+3+7+8+9}{1+4+6+8+9}{1+5+6+7+9}{2+3+6+8+9}{2+4+5+8+9}{2+4+6+7+9}{2+5+6+7+8}{3+4+5+7+9}{3+4+6+7+8} 9
29 {1+4+7+8+9}{1+5+6+8+9}{2+3+7+8+9}{2+4+6+8+9}{2+5+6+7+9}{3+4+5+8+9}{3+4+6+7+9}{3+5+6+7+8} 8
30 {1+5+7+8+9}{2+4+7+8+9}{2+5+6+8+9}{3+4+6+8+9}{3+5+6+7+9}{4+5+6+7+8} 6
31 {1+6+7+8+9}{2+5+7+8+9}{3+4+7+8+9}{3+5+6+8+9}{4+5+6+7+9} 5
32 {2+6+7+8+9}{3+5+7+8+9}{4+5+6+8+9} 3
33 {3+6+7+8+9}{4+5+7+8+9} 2
34 {4+6+7+8+9} 1
35 {5+6+7+8+9} 1

6-Cell Runs

Sum range: 21–39  ·  4 forced combinations

Sum Valid combinations Count
21 {1+2+3+4+5+6} 1
22 {1+2+3+4+5+7} 1
23 {1+2+3+4+5+8}{1+2+3+4+6+7} 2
24 {1+2+3+4+5+9}{1+2+3+4+6+8}{1+2+3+5+6+7} 3
25 {1+2+3+4+6+9}{1+2+3+4+7+8}{1+2+3+5+6+8}{1+2+4+5+6+7} 4
26 {1+2+3+4+7+9}{1+2+3+5+6+9}{1+2+3+5+7+8}{1+2+4+5+6+8}{1+3+4+5+6+7} 5
27 {1+2+3+4+8+9}{1+2+3+5+7+9}{1+2+3+6+7+8}{1+2+4+5+6+9}{1+2+4+5+7+8}{1+3+4+5+6+8}{2+3+4+5+6+7} 7
28 {1+2+3+5+8+9}{1+2+3+6+7+9}{1+2+4+5+7+9}{1+2+4+6+7+8}{1+3+4+5+6+9}{1+3+4+5+7+8}{2+3+4+5+6+8} 7
29 {1+2+3+6+8+9}{1+2+4+5+8+9}{1+2+4+6+7+9}{1+2+5+6+7+8}{1+3+4+5+7+9}{1+3+4+6+7+8}{2+3+4+5+6+9}{2+3+4+5+7+8} 8
30 {1+2+3+7+8+9}{1+2+4+6+8+9}{1+2+5+6+7+9}{1+3+4+5+8+9}{1+3+4+6+7+9}{1+3+5+6+7+8}{2+3+4+5+7+9}{2+3+4+6+7+8} 8
31 {1+2+4+7+8+9}{1+2+5+6+8+9}{1+3+4+6+8+9}{1+3+5+6+7+9}{1+4+5+6+7+8}{2+3+4+5+8+9}{2+3+4+6+7+9}{2+3+5+6+7+8} 8
32 {1+2+5+7+8+9}{1+3+4+7+8+9}{1+3+5+6+8+9}{1+4+5+6+7+9}{2+3+4+6+8+9}{2+3+5+6+7+9}{2+4+5+6+7+8} 7
33 {1+2+6+7+8+9}{1+3+5+7+8+9}{1+4+5+6+8+9}{2+3+4+7+8+9}{2+3+5+6+8+9}{2+4+5+6+7+9}{3+4+5+6+7+8} 7
34 {1+3+6+7+8+9}{1+4+5+7+8+9}{2+3+5+7+8+9}{2+4+5+6+8+9}{3+4+5+6+7+9} 5
35 {1+4+6+7+8+9}{2+3+6+7+8+9}{2+4+5+7+8+9}{3+4+5+6+8+9} 4
36 {1+5+6+7+8+9}{2+4+6+7+8+9}{3+4+5+7+8+9} 3
37 {2+5+6+7+8+9}{3+4+6+7+8+9} 2
38 {3+5+6+7+8+9} 1
39 {4+5+6+7+8+9} 1

7-Cell Runs

Sum range: 28–42  ·  4 forced combinations

Sum Valid combinations Count
28 {1+2+3+4+5+6+7} 1
29 {1+2+3+4+5+6+8} 1
30 {1+2+3+4+5+6+9}{1+2+3+4+5+7+8} 2
31 {1+2+3+4+5+7+9}{1+2+3+4+6+7+8} 2
32 {1+2+3+4+5+8+9}{1+2+3+4+6+7+9}{1+2+3+5+6+7+8} 3
33 {1+2+3+4+6+8+9}{1+2+3+5+6+7+9}{1+2+4+5+6+7+8} 3
34 {1+2+3+4+7+8+9}{1+2+3+5+6+8+9}{1+2+4+5+6+7+9}{1+3+4+5+6+7+8} 4
35 {1+2+3+5+7+8+9}{1+2+4+5+6+8+9}{1+3+4+5+6+7+9}{2+3+4+5+6+7+8} 4
36 {1+2+3+6+7+8+9}{1+2+4+5+7+8+9}{1+3+4+5+6+8+9}{2+3+4+5+6+7+9} 4
37 {1+2+4+6+7+8+9}{1+3+4+5+7+8+9}{2+3+4+5+6+8+9} 3
38 {1+2+5+6+7+8+9}{1+3+4+6+7+8+9}{2+3+4+5+7+8+9} 3
39 {1+3+5+6+7+8+9}{2+3+4+6+7+8+9} 2
40 {1+4+5+6+7+8+9}{2+3+5+6+7+8+9} 2
41 {2+4+5+6+7+8+9} 1
42 {3+4+5+6+7+8+9} 1

8-Cell Runs

Sum range: 36–44  ·  9 forced combinations

Sum Valid combinations Count
36 {1+2+3+4+5+6+7+8} 1
37 {1+2+3+4+5+6+7+9} 1
38 {1+2+3+4+5+6+8+9} 1
39 {1+2+3+4+5+7+8+9} 1
40 {1+2+3+4+6+7+8+9} 1
41 {1+2+3+5+6+7+8+9} 1
42 {1+2+4+5+6+7+8+9} 1
43 {1+3+4+5+6+7+8+9} 1
44 {2+3+4+5+6+7+8+9} 1

9-Cell Runs

Sum range: 45–45  ·  1 forced combination

Sum Valid combinations Count
45 {1+2+3+4+5+6+7+8+9} 1

Summary: forced combinations by run length

A forced combination has exactly one valid digit set for the given sum. Memorise these first — they require no deduction and immediately fill cells.

Run length Sum range Forced sums Forced / Total
2 cells 3–17 3, 4, 16, 17 4 / 15
3 cells 6–24 6, 7, 23, 24 4 / 19
4 cells 10–30 10, 11, 29, 30 4 / 21
5 cells 15–35 15, 16, 34, 35 4 / 21
6 cells 21–39 21, 22, 38, 39 4 / 19
7 cells 28–42 28, 29, 41, 42 4 / 15
8 cells 36–44 36, 37, 38, 39, 40, 41, 42, 43, 44 9 / 9
9 cells 45–45 45 1 / 1

How to use this table

Step 1 — Find your run length and sum

Count the white cells in the run (that is the run length) and read the clue value (that is the sum). Jump to the matching section above.

Step 2 — Read the valid combinations

Each set in curly braces is one possible group of digits. For example, a 3-cell run summing to 9 can be solved with {1+2+6}, {1+3+5}, or {2+3+4}.

Step 3 — Eliminate via crossing runs

If a crossing run already contains the digit 6, eliminate any combination that includes 6. Repeat across all intersections until one combination remains.

Forced combinations (★)

When only one combination is listed, the digit set is forced. You know which digits appear — you just need to determine their order from the crossing runs. Start your solve with these.

Quick-reference: the most useful forced combinations

These appear constantly in easy and medium puzzles. Memorise these eight and your first scan of any grid will unlock cells immediately.

Run Sum Forced digits
2 cells3{1, 2}
2 cells17{8, 9}
3 cells6{1, 2, 3}
3 cells24{7, 8, 9}
4 cells10{1, 2, 3, 4}
4 cells30{6, 7, 8, 9}
5 cells15{1, 2, 3, 4, 5}
5 cells35{5, 6, 7, 8, 9}