Math calculator
Permutation and Combination Calculator
Calculate permutations and combinations for choosing r items from n items.
Formula
Counting arrangements
nPr = n! / (n - r)!; nCr = n! / (r! x (n - r)!)
Choosing 3 from 10 gives 720 permutations and 120 combinations.
FAQs
What is the difference between permutation and combination?+
Permutations count order. Combinations ignore order.
Why is r capped?+
Large factorials grow quickly, so the calculator keeps inputs in a practical range.
How does the Permutation and Combination Calculator calculate the result?+
It uses the Counting arrangements: nPr = n! / (n - r)!; nCr = n! / (r! x (n - r)!). Choosing 3 from 10 gives 720 permutations and 120 combinations.
What information do I need to use the Permutation and Combination Calculator?+
Calculate permutations and combinations for choosing r items from n items.
How accurate is the Permutation and Combination Calculator?+
Permutation and Combination Calculator applies the formula and assumptions shown on this page. Results may be rounded for readability, so verify changing rates, thresholds, medical guidance, or legal rules with the cited source or a qualified professional.
What should I check before using the Permutation and Combination Calculator result?+
Check that the units, dates, rates, and assumptions match your situation. Change one input at a time to understand which values have the largest effect on the result.
Math guide
How to use the Permutation and Combination Calculator
Calculate permutations and combinations for choosing r items from n items. The page also explains the counting arrangements and shows a practical example: Choosing 3 from 10 gives 720 permutations and 120 combinations.
- 1
Enter your details
Enter n items, then complete any other fields shown in the calculator.
- 2
Check the calculation
Review the result alongside the counting arrangements: nPr = n! / (n - r)!; nCr = n! / (r! x (n - r)!).
- 3
Compare scenarios
Change one or more inputs to see how they affect the permutation and Combination Calculator result before you use the estimate.
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