Math
Permutation Calculator
Find how many ways r items can be chosen and arranged in order from n items.
Formula
Permutation P(n, r) = n! ÷ (n − r)!, because order matters when arranging the chosen items.
How it works
Enter n and r with r no larger than n. The calculator divides the factorials. For example, P(10, 3) = 720.
FAQs
What does the Permutation do?
It takes the values you enter and works out the permutation for you, showing the result straight away.
What should I enter?
Enter ordinary numbers in the boxes above. If a value does not make sense for this calculation, the page will ask you to check it instead of showing a wrong answer.
Can I use the result for homework or everyday maths?
Yes. It is a general-purpose maths helper; for exam or professional work, still check the steps against your own working.