# How to Calculate Factorial?

How to calculate factorial of a number?

## Factorial Calculation

Factorial is defined as the product of positive integer with all its lowest value numbers. It is denoted by the symbol **(!)**. Learn how to calculate factorial by following the simple steps given below

**Formula for Factorial Calculation**:

**n! = n x (n "“ 1) x (n "“ 2) Â· Â· Â· 3 x 2 x 1**

**Step 1:** Let us consider an example, What is 5!?

Here, n = 5

**Step 2:** Substitute the values in the formula,

5! = 5 x (5-1) x (5-2) x (5-3) x (5-4)

= 5 x 4 x 3 x 2 x 1

= 20 x 6

= 120

The factorial of 5 is **120**.

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