n! Factorial Calculator (n!)
Compute factorial of any natural number with full precision
📌 What is factorial?
The factorial (n!) is the product of all positive integers from 1 to n. For example, 5! = 1×2×3×4×5 = 120. By definition, 0! = 1.
Factorials are heavily used in probability, statistics, and combinatorics.
Compute the Factorial of Any Number
The factorial of a number, written with an exclamation mark as n!, is the product of every whole number from one up to n. So five factorial means five times four times three times two times one, which equals 120. This calculator does that multiplication for you instantly, letting you enter a value and read the exact result without chaining the numbers together by hand.
Factorials grow extraordinarily fast, and even modest inputs produce huge values that overflow ordinary calculators. This tool uses arbitrary-precision arithmetic so that large factorials are returned in full, digit for digit, rather than rounded into scientific notation. By definition zero factorial equals one, a convention the calculator follows so your results stay consistent with standard mathematics.
Why Factorials Matter
Factorials are the backbone of counting problems. They count the number of ways to arrange a set of items, and they appear throughout permutations, combinations, probability, and statistics. They also show up in series expansions used across calculus and engineering. Whether you are a student verifying a probability exercise or anyone needing an exact arrangement count, enter your number and get a precise factorial in a single step.