Enter n, r, and the counting mode to calculate an exact permutation or combination count.
Exact Count
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Enter total items, chosen items, and the counting mode to get the exact count and formula.
Tap an example to prefill the calculator with sample values.
Lottery-style combination
Choose 6 numbers from 49
An unordered selection without repetition is the classic combination example.
Result: The exact count is huge because the search space grows quickly even without order
4-digit passcode
10 digits with repetition allowed
Ordered selections with repetition model most simple PIN or code-style counts.
Result: Order matters, so the count is much larger than a combination case