Factorial Calculator
Compute the exact factorial of a nonnegative whole number, including 0!.
Loading tool…
How to use Factorial Calculator
The factorial n! multiplies all integers from 1 through n. By convention, 0! equals 1. BigInt preserves the integer result exactly.
- Enter nonnegative integer n.
- Check that the input follows the stated limits and uses consistent units.
- Run the calculator, review the result, then copy or download it.
Good to know
- The input is a whole number from 0 to 1,000. Fractional factorials and the gamma function are not supported.
- Decimal inputs have at most 120 characters and magnitude from 1e-100 to 1e15, or zero. Floating-point results are rounded to 12 significant digits; extreme derived results may underflow or be rejected. Exact integer results are identified separately.
Common questions
What calculation does Factorial Calculator perform?
The factorial n! multiplies all integers from 1 through n. By convention, 0! equals 1. BigInt preserves the integer result exactly.
Why does 0! equal 1?
It is the empty-product identity, which keeps formulas such as combinations consistent at zero.
Keep going with related tools
All math →Descriptive Statistics Calculator
Summarize a numeric list with mean, median, modes, range, count, and sum.
MathFraction Calculator
Add, subtract, multiply, or divide two fractions and reduce the exact result.
EducationCombination and Ordered Selection Ranking
Rank or recover a combination or ordered selection by exact zero-based lexicographic index without enumerating all objects.
MathArithmetic and Geometric Sequence Calculator
Find a progression’s nth term and finite sum with explicit zero-count and unit-ratio behavior.