Factorial Calculator
Calculate n! (n factorial) for any non-negative integer. Shows the full expansion.
! =
What is a Factorial?
n! = n × (n−1) × (n−2) × … × 2 × 1
5! = 5 × 4 × 3 × 2 × 1 = 120
0! = 1 (by definition)
0! = 1 (by definition)
Factorial Reference Table
| n | n! |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 5 | 120 |
| 10 | 3,628,800 |
| 15 | 1,307,674,368,000 |
| 20 | 2,432,902,008,176,640,000 |
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Last updated: 2026-08-08