OnlineSciCalc Home Guide Tools

Combination / Permutation Calculator

Number of objects
Total :
Choose :
Replacements :
Combinations :
Permutations :


n=number of objects in total
r=number of objects to choose



With Replacements




With Replacements


How do I use the Combination / Permutation calculator?

  • Enter the total number of objects to choose from (Total)
  • Enter the number of objects you want to choose (Choose)
  • Choose must be less than or equal to Total (≤)
  • Select whether replacements are allowed
  • See the results appear instantly

How to think about combinations and permutations

Let's use an example - choose 3 letters from the alphabet:

When counting combinations:

  • [a, b, c] is the same combination as [c, b, a]
  • both represent the choice of letters a, b, and c. In any order. Order doesn't matter.

When counting permutations:

  • [a, b, c] is a different permutation than [c, b, a]
  • [a, b, c] represents the choice of a, then b, then c. In that particular order.
  • [c, b, a] represents the choice of c, then b, then a. In that particular order.
  • Order matters.


  • A combination refers to the number of ways to choose elements from a set, in any order.
  • A permutation refers to the number of ways to choose elements from a set, in a particular order.