Compute n! instantly — exact big-number results with step-by-step breakdown
Factorial Calculator
Result
Step-by-step Multiplication
Starting from 1, multiply each integer up to 10.
| Step | Multiply by | Running product |
|---|---|---|
| 1 | × 1 | 1 |
| 2 | × 2 | 2 |
| 3 | × 3 | 6 |
| 4 | × 4 | 24 |
| 5 | × 5 | 120 |
| 6 | × 6 | 720 |
| 7 | × 7 | 5,040 |
| 8 | × 8 | 40,320 |
| 9 | × 9 | 362,880 |
| 10 | × 10 | 3,628,800= 10! |
About Factorials
A factorial calculator lets you compute n! — the product of all positive integers from 1 to n — instantly and exactly. Unlike floating-point tools, this calculator uses JavaScript BigInt arithmetic so every digit is correct, no matter how large n gets. Enter any non-negative integer to see the full result, its digit count, and a clear step-by-step multiplication table showing how the answer is built.
The factorial of a non-negative integer n, written n!, is the product of all positive integers from 1 up to n. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120. By convention, 0! = 1.
This tool supports n up to 10,000. At that size, 10000! has over 35,000 digits. Results are computed with exact BigInt arithmetic — there is no floating-point rounding or scientific-notation approximation.
0! = 1 by convention, defined as the empty product (the product of no numbers). This is consistent with combinatorics: there is exactly one way to arrange zero items, and it keeps the recursive formula n! = n × (n−1)! valid at n = 1.
Factorials appear in combinatorics (counting permutations and combinations), probability theory, calculus (Taylor series), and computer science algorithms. For instance, the number of ways to arrange n distinct objects in a row is exactly n!.