Factorial Calculator
Calculate n factorial for a nonnegative whole number.
Factorial Calculator
How this calculator works
The factorial n! multiplies every positive integer from 1 through n. By definition, 0! = 1. Factorials are used in counting, probability, permutations, and combinations.
When to use it
Use this calculator to check homework, verify a manual calculation, compare examples, and explore how changing each input affects the result. Enter all measurements in compatible units and interpret the answer within the context of your problem.
Formula and examples
The factorial n! multiplies every positive integer from 1 through n. By definition, 0! = 1. Factorials are used in counting, probability, permutations, and combinations.
Can I use decimal values?
Decimal values are supported when the mathematical operation permits them. Factorials require nonnegative whole numbers.
Why might a result be undefined?
Some operations have restrictions, such as division by zero, invalid logarithm bases, or a zero leading coefficient in a quadratic equation.