Factorial (n!) Calculator

factorial of a number calculator - formula, step by step calculation & solved example problems online to calculate the factorial of a given number (positive integer) n. Factorial often written with the exclamation sign: n!, is the result of series consecutive numbers product less than or equal to n (i.e) from given number to 1 as examples given below.
0! = 1
1! = 1
2! = 2 x 1 = 2
3! = 3 x 2 x 1 = 6
4! = 4 x 3 x 2 x 1 = 24
5! = 5 x 4 x 3 x 2 x 1 = 120 and so on.
In mathematics, the product of all positive integers less than or equal to n (i.e) n! = n x (n-1) x (n-2) x .... x 1. The value of 0! = 1. The factorial function is extensively used in permutaions (nPr) & combinations (nCr), probability & statistics, calculus, algebra & other advanced mathematical analysis.

Factorial Formula

The below mathematical formula is used in this calculator to find the factorial of a given positive number n!

Solved Example

The below solved example may be useful to understand how the values are being used in the mathematical formulas to determine the factorial of a number.

Example Problem :
Find the factorial for the integer 7?

Solution :
Data given
n = 7

Step by step calculation
formula to find n! = n x (n-1) x (n-2) x .... x 1
substitute the values
n! = 7 x 6 x 5 x 4 x 3 x 2 x 1
n! = 5040

The factorial is an important function in the field of statistics & probability. The above formulas, step by step calculation & solved example may be useful to understand how to determine the factorial of a number but for fast computation, when it comes to online this factorial calculator may be useful to perform & verify your such calculations online.