About permutations (nPr)
This calculator works out nPr — the number of ways to arrange r items from a set of n when order matters. Enter n and r and it returns the count using nPr = n! / (n − r)!. It runs in your browser.
How Permutations works
How to use it
- Enter n (total items) and r (how many to arrange).
- Read the number of permutations.
How it works
A permutation counts ordered arrangements — first, second and third place are different outcomes. The tool multiplies n × (n−1) × … for r terms, which equals n! / (n − r)!.
Common uses
- Count ordered arrangements
- Work out race finishing orders
- Count passwords or codes
- Solve probability problems
- Help with statistics homework
- Count seating orders
- Plan ordered selections
- Learn combinatorics
Frequently asked questions
What is nPr?
The number of ordered arrangements of r items from n.
What is the formula?
nPr = n! / (n − r)!.
How is it different from combinations?
Permutations count order; combinations do not.
What if r is greater than n?
That is invalid — r cannot exceed n.
Is my input uploaded?
No — it calculates in your browser.
Can it handle big numbers?
Yes — large results are shown clearly.
Is it free?
Yes — completely free with no sign-up.