Permutations and Combinations Calculator

Instantly evaluate $nCr$ and $nPr$ probability values with extreme precision. Analyze repetitive subsets and circular permutations effortlessly.

n =
0 Max (200)
r =
0 Max (200)
Total Combinations $C(n, r)$
120
Order does not matter
Total Permutations $P(n, r)$
720
Order strictly matters
Combinations (With Repetition)
220
$C'(n, r) = \frac{(n+r-1)!}{r!(n-1)!}$
Permutations (With Repetition)
$n^r$ repetition format
1000

Mathematical Properties Breakdown

Step / Formula Aspect
Expression
Evaluated Result

Calculation History Log

Logged Time Pool ($n$) Choice ($r$) $C(n, r)$ (Combinations) $P(n, r)$ (Permutations)
No computations logged yet. Interactive runs exceeding 2 seconds will record here.

What Is a Permutations and Combination Calculator?

A Permutations and Combination Calculator is a free online tool designed to evaluate permutations and combinations online using standard mathematical nPr and nCr formulas. It determines the total quantity of distinct pathways to pick r items out of n items when order is neglected. Whether you are resolving complex probability formulas, studying discrete math, or arranging statistical subsets, this combination calculator with steps yields real-time, precision-mode results.

Unlike manual calculations that force you to calculate factorials step by step, this nCr calculator with solution handles massive computations instantaneously using advanced client-side BigInt technologies to avoid memory overflow or rounding errors.

Check Out Our High-Precision Binary Calculator

How to Use This Combination Calculator

Combination vs Permutation

The difference between combinations and permutations is straightforward: combinations ignore the order of selection, whereas permutations treat different ordering sequences as unique outcomes.

Combination Formula ($nCr$) with Steps

This combination calculator with formula runs standard combinations using:

C(n, r) = n! / [r! * (n - r)!]

Where:

Frequently Asked Questions

What is a Combination Calculator?

It is an educational utility used to determine the total number of unique arrangements possible when choosing $r$ elements from a set of $n$ elements, either ignoring or honoring the sequence order.

What is the circular permutation feature?

Circular permutations represent the number of ways to arrange $n$ unique objects around a circular loop. The formula used is $(n - 1)!$, because there is no designated "start" position in a true circle.

How does combination with repetition differ?

In standard combinations, once an item is selected, it cannot be chosen again. In combinations with repetition, elements can be selected multiple times, allowing sets like [A, A, B].

Why does BigInt matter in these equations?

Standard numbers in JavaScript lose precision above $2^{53} - 1$. Factorials scale up incredibly quickly (for example, $40!$ is massive). BigInt allows us to calculate factorials up to $2000!$ with perfect, absolute precision.