What is Permutation Calculator?
Permutation Calculator helps you count ordered arrangements when selecting items from a group.
The main result is permutations. The formula, example and assumptions below explain how to interpret it.
How to use Permutation Calculator
Use the example to get familiar with the form, then enter your own figures. Any rates in the example are illustrative. Check the field labels and units before calculating.
- Gather number of items (n) and items selected (r). Use values from the same situation or reporting period.
- Replace the example number of items (n) with your own value, then complete the other fields. Check the displayed units.
- Select Calculate and read permutations. Change one input and calculate again to compare a second scenario. Reset restores the original example.
- Enter number of items (n), at least 0 and at most 1000. Use a whole number.
- Enter items selected (r), at least 0 and at most 1000. Use a whole number.
Permutation Calculator: a worked example
With the inputs below, the result is 720 (permutations). Follow the example, then replace these illustrative values with your own.
| Input or output | Example value |
|---|---|
| Number of items (n) | 10 |
| Items selected (r) | 3 |
| Permutations | 720 |
Understanding the Permutation result
The main output is permutations. It applies to the inputs and operation you selected.
Displayed results use a readable number of decimal places. When checking a result by hand, keep extra precision until the last step. To compare scenarios, change one input at a time and keep the others fixed.
Permutation Calculator: assumptions and common mistakes
A useful estimate starts with the right inputs. Check the following assumptions and limits before applying the result to your situation.
- Check the base value, sample definition and chosen operation. Display rounding should come after the calculation.
For wider guidance, visit NIST statistical handbook. The formula and scope of this specific tool are stated on this page.






