Classic tool
Permutation and Combination Calculator
Calculate nPr and nCr to compare ordered arrangements and unordered selections.
Use this permutation and combination calculator to count how many ways items can be arranged or selected without repetition. It is useful for combinatorics homework, probability practice, contest scenarios, team building, seating plans and any task where you need a reliable count of possibilities.
Enter the total number of available items in n and the number selected in r. The tool returns nPr when order matters, such as podium places, passwords or ranked positions, and nCr when only the chosen group matters, such as committees, lottery picks or bundle choices.
Because these totals grow very quickly, the calculator keeps exact integer results instead of rounding them. If r is greater than n or the input contains decimals or text, the page flags the issue before you rely on the count.
Use clear inputs to get a more useful result.
How to use Permutation and Combination Calculator
Open the tool, fill in the fields with the data you already have and generate the result step by step. If you want to compare scenarios, change one field at a time so it is easier to understand the impact of each value.
When Permutation and Combination Calculator is useful
The goal here is simple: Calculate nPr and nCr to compare ordered arrangements and unordered selections. It works well for quick checks, planning, study and review before you move to a final decision or document.
What to review before using the result
Check units, labels, numbers, timing and any context that can change the meaning of the output. If the result will be used in a quote, technical task, published page or report, finish with a manual review.
Frequently asked questions
What should I prepare before using the tool?
Keep the key values, labels and units ready before filling in the fields. Cleaner inputs make the final result easier to review and compare.
Can I test different scenarios on the same page?
Yes. The safest approach is to change one field at a time, compare the outputs and note which value actually changes the final answer.
Is the result ready to use without checking it?
It is better to treat it as support. Review the output once more before using it in a quote, document, spreadsheet, technical task or published page.