Factorial Calculator
Solve any positive integer factorial value instantly with detailed multiplying expansions.
Enter Value
Factorial Result
120
Series Multiplication Expansion:
What is the Factorial Calculator?
The Factorial Calculator evaluates the product of an integer and all the positive integers below it. Factorials grow exponentially fast and are crucial in statistics for calculating permutations, combinations, and probability distributions.
How It Works (Formula)
A factorial is denoted by an exclamation mark ($n!$). The algorithm multiplies the target number by the next integer down, and the next, all the way until it hits 1. By mathematical definition, the factorial of zero ($0!$) is exactly 1.
$$ n! = n \times (n-1) \times (n-2) \times \dots \times 1 $$
The continuous product rule for a mathematical factorial.
How to Use It
Enter a positive whole number into the calculator (e.g., entering 5 will calculate $5 \times 4 \times 3 \times 2 \times 1$). The tool will use big-number processing to output the massive expanded integer result without error.