Factorial Calculator
Compute n! exactly, even for huge n.
Full value
3628800
Computed with BigInt so the answer stays exact for any n up to 2000. 0! is defined as 1. Past about n=170 the value exceeds JavaScript's regular number range, which is why factorial calculators that use floats lose precision.
About
Punch in n and get the full value of n factorial. Uses BigInt internally so the answer stays exact for any n up to 2000 (a 5,735-digit number). Most factorial calculators silently lose precision past n=170 because they use floating-point.
How to use
- Enter n.
- Read the exact value, digit count, and scientific notation.
FAQ
Why does this go to 2000?+
BigInt makes huge integers exact, but the string can get unwieldy. 2000! has about 5,735 digits, which is a lot of scrolling but still fits on the page.
What is 0!?+
By definition, 0! = 1. It comes from the empty product convention; it also makes combinatorics formulas work cleanly.