Enter a non-negative whole number and get its factorial, written as n with an exclamation mark. The factorial of n is the product of every whole number from one up to n, so five factorial is one times two times three times four times five, which equals one hundred twenty. Factorials grow extremely fast and show up everywhere in combinatorics, probability, and series expansions. This calculator uses JavaScript BigInt so the answer stays exact even when it has hundreds of digits, unlike floating point tools that silently lose precision. By definition zero factorial equals one, and negative or fractional inputs are rejected. Type your number and read the full result. Everything is computed locally in your browser, so there is nothing to upload and no waiting on a server.
n factorial, written n!, is the product of all positive integers from 1 up to n, so 5! equals 5 times 4 times 3 times 2 times 1, which is 120.
By definition 0! equals 1, which keeps formulas for permutations and combinations consistent.
It uses big-integer math, so results for large inputs are exact with no rounding or scientific-notation approximation.
Enter a non-negative whole number and get its factorial, written as n with an exclamation mark. The factorial of n is the product of every whole number from one up to n, so five factorial is one times two times three times four times five, which equals one hundred twenty.
Yes. Factorial Calculator is completely free, with no sign-up and no usage limits.
Yes. Factorial Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Factorial Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.