Killer Sudoku cage calculator
Only here Narrows every cage combination by the digits you have ruled in or out and names the digits every remaining combination needs, with a rule-of-45 helper and 6×6 Killer support.
Pick a cage size and sum to see every set of different digits it can hold. Mark the digits you already know are in or out, and the list narrows to what's left, with the digits every remaining combination needs.
Tap a digit once if it must be in the cage, twice if it can't be, three times to reset.
8 combinations for 3 squares summing to 15.
- 159
- 168
- 249
- 258
- 267
- 348
- 357
- 456
- In every combination
- none
- In none of them
- none
Sums with only one combination for 3 squares: 6, 7, 23, 24.
Rule of 45
Every row, column and box adds up to 45. Pick how many whole rows, columns or boxes you're looking at, list the sums of the cages that sit inside them, and add the part of any cage that sticks outside.
The uncaged squares sum to 45 (45 − 0).
How it works
A cage holds different digits that add up to its sum, so the calculator lists every set of distinct digits of the right size with that total. It checks all of them, so the list is complete: across every size and sum there are exactly 511 combinations for digits 1 to 9.
In every combination are digits the cage must contain whichever combination is right; in none of them are digits it can't contain. Both update as you rule digits in or out.
The rule of 45: every row, column and box adds up to 45 (21 on 6×6), so if you know the cages inside some whole houses, the squares left over sum to the difference. When a cage pokes outside those houses, add the part outside to the leftover.
Not affiliated with any puzzle publisher.