Permutation Calculator
Calculate the number of possible arrangements when order matters.
Permutations (nPr): —
Permutation formula: nPr = n! / (n − r)!
Example
If you have 5 books and choose 3 to arrange on a shelf:
n = 5
r = 3
Permutations = 5 × 4 × 3 = 60
What does this calculator do?
It calculates the number of possible ordered arrangements of r items selected from n distinct items.
When should you use permutations?
Use permutations when the order of selection matters, such as rankings, seating arrangements, or ordered codes.
Frequently Asked Questions
Can r be greater than n?
No. The number of selected items cannot exceed the total number of items.
Does this calculator use factorials?
Yes. The permutation formula is based on factorial calculations.
Is the result always an integer?
Yes. Permutation counts are always whole numbers.