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

## Choose Definition

Choose is a term used in math to describe the operation of taking the combination of two numbers.

## How to calculate choose?

How to calculate a combination

**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.

**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.

**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.