❗ Factorial Calculator
How It Works
Calculate the factorial of a non-negative integer. Get a clear result with the inputs shown on the page. Use Factorial Calculator to apply the displayed mathematical method to your values and see the result immediately.
The result is most useful when the inputs match the definitions used by this calculator. For this tool, the underlying method is: n! = n × (n−1) × ... × 1. Compare the output with the worked example, then change one meaningful input at a time to see how the result responds.
Understanding Factorial
Factorial describes a mathematical relationship between the values entered in the calculator. Understanding the reference values and formula helps you interpret the result correctly. Check units, signs, reference values, and rounding conventions when using the result for an important calculation. Review the factorial inputs and units before relying on the result.
When to Use This Calculator
Use Factorial Calculator to apply the displayed mathematical method to your values and see the result immediately.
Practical tip: For this Factorial Calculator, identify the reference values and units first, then change one meaningful input at a time so the effect on the result is clear.
Formula
n! = n × (n−1) × ... × 1
Example
5! = 120. Try changing one input to see how the result responds.