Permutation and Combination Calculator
nPr = n!/(n−r)!; nCr = n!/[r!(n−r)!]; ordered repetition = nʳ.
Inputs and units
- Available items n: Enter your value in the format and unit shown.
- Selected items r: Enter your value in the format and unit shown.
- Counting rule: Choose Permutations (ordered), Combinations (unordered), Ordered selections with repetition.
Calculation method
nPr = n!/(n−r)!; nCr = n!/[r!(n−r)!]; ordered repetition = nʳ.
Worked example
The example values are: Available items n = 10; Selected items r = 3; Counting rule = p
- Count: 720
- Precision: Exact to integer precision
Assumptions and limitations
Check that the inputs and units describe your situation.
Using your result
Select Calculate after changing inputs. Copy result copies the displayed output; Download result saves a text file. Reset returns the form to its example inputs. Calculations run in your browser.
Permutation and Combination Calculator FAQs
What method does this calculator use?
nPr = n!/(n−r)!; nCr = n!/[r!(n−r)!]; ordered repetition = nʳ.
What should I check before using the result?
Check that the inputs and units describe your situation.