Permutation & Combination Calculator
Result
Permutations P(10, 3) = nPr 720 Ordered arrangements of 3 from 10
Combinations C(10, 3) = nCr Unordered selections of 3 from 10 120
nPr / nCr (= r!) The ratio equals r! — the number of ways to arrange r items. 6
Permutation & Combination Calculator is a mathematics calculator that helps you calculate permutation & combination values from your input data. The formula used is: nPr = n! / (n−r)! (order matters). nCr = n! / (r! × (n−r)!) (order does not matter). nPr = nCr × r!. Ensure all inputs share the same unit system (e.g. all metres or all feet) unless the formula converts between units.
Formula
nPr = n! / (n−r)! (order matters). nCr = n! / (r! × (n−r)!) (order does not matter). nPr = nCr × r!
- Permutation & Combination Calculator gives you a fast estimate using your inputs and updates instantly when you change any value.
- Formula: nPr = n! / (n−r)! (order matters). nCr = n! / (r! × (n−r)!) (order does not matter). nPr = nCr × r!
- Input definitions: • Total items (n): the numeric total items (n) used in the calculation • Items to select (r): the numeric items to select (r) used in the calculation
- Manual method: write down each input, apply the formula step by step, then compare your manual result with the calculator output.
- Ensure all inputs share the same unit system (e.g. all metres or all feet) unless the formula converts between units.
- Results are mathematically exact given the formula and your inputs. Rounding to decimal places may introduce small display differences.
- Check that all inputs are in the valid range for the formula. Some operations (e.g. square root, division) require non-negative or non-zero values.
- Practical tip: test a low, medium, and high scenario to understand sensitivity before making decisions.
Example Calculation
Inputs
- Total items (n): 10
- Items to select (r): 3
Suppose you enter: Total items (n) = 10, Items to select (r) = 3. The calculator applies the formula (nPr = n! / (n−r)! (order matters). nCr = n! / (r! × (n−r)!) (order does not matter). nPr = nCr × r!) and shows all output values below. Change any input field to immediately see how the result changes.
Frequently asked questions
What is the Permutation & Combination?
The Permutation & Combination Calculator is a mathematics calculator that helps you calculate permutation & combination values from your input data. Ensure all inputs share the same unit system (e.g. all metres or all feet) unless the formula converts between units.
When should I use this calculator?
Use this calculator whenever you need a quick, accurate result for permutation & combination values from your input data without working through the arithmetic manually.
What units should I enter?
Ensure all inputs share the same unit system (e.g. all metres or all feet) unless the formula converts between units.
How accurate are the results?
Results are mathematically exact given the formula and your inputs. Rounding to decimal places may introduce small display differences.
How do I interpret the result?
Check that all inputs are in the valid range for the formula. Some operations (e.g. square root, division) require non-negative or non-zero values.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.
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