# Choose Calculator (C(n,r))

Enter a number n and number r into the choose calculator. The combination calculator will return the value of n choose r.

## Choose Formula

The following formula is used to calculate n choose r given two integers n and r.

C(n,r)=(nr)=n!/(r!(n−r)!)

• Where n is an integer
• r is an integer
• and ! is factorial

How to calculate a combination

1. First, determine the number of options to choose from

This will be the number n in the formula above. It will be all the available options to choose from.

2. Next, determine the number of options you wish to choose

This will be the number of objects or options you choose out of the total number of option.

3. Calculate the combination

Calculate n choose r using the formula above.

## FAQ

What is n choose r?

N choose r is another way of saying the mathematical operation of a combination.

What is a combination?

In mathematical terms, a combination is as it sounds, it’s a numerical operation that displays the total number of options to choose from given a set of objects or numbers. The combination will yield all possibly combinations of r integers from a set of n integers. For example, let’s say we have a set of numbers 1,2,3. We want to chose all possible combinations of 2 integers. This yields the following: 1,2 / 1,3 / 2,3 = 3 total combinations.