Permutation and Combination Calculator

Enter n and r, choose whether order matters and whether repetition is allowed, then inspect the exact count, formula, digit length, and comparison context.

Total items n

Chosen items r

Order

Repetition

Choose whether order matters and whether a chosen item may repeat.

Formula

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

Counts are exact integers. Without repetition, r cannot exceed n. Circular arrangements and repeated-choice special cases also have dedicated tools.

Core describe → test → interpret workflows

Use descriptive context first, choose the method that matches the design, then keep inputs, settings and result evidence reproducible instead of copying a p-value without its analysis recipe.

Start: Statistics Calculator Choose a statistical test

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Interpret statistical results in context

Use plots and descriptive summaries before formal tests. Check the sampling/design assumptions that matter for the chosen method, report effect size and uncertainty where available, and avoid treating a threshold such as p < .05 as proof of importance, causation, or truth. Browser calculations are educational/planning utilities, not domain-specific professional advice.

How to use this Permutation and Combination Calculator

Enter n and r, choose whether order matters and whether repetition is allowed, then inspect the exact count, formula, digit length, and comparison context.