Factorial Calculator
Multiply the positive integers through n for small combinatorics calculations. The supported range preserves exact integer results.
How to use Factorial Calculator
- Enter “Whole number (0–18)”, using the units and limits shown in its label.
- Select Calculate or Process. Review the result and any validation message before copying or downloading available output. Reset clears the result and restores the starting inputs.
Method & assumptions
n! = 1 × 2 × … × n; 0! = 1.
Worked example
5! = 120.
Results and projections are informational estimates, not financial, medical, legal, tax, or property advice. Check assumptions, units, rounding, and local requirements independently. Investment illustrations do not guarantee returns. Keep original files and check transformed output before use.
Questions, answered
Why stop at 18?
19! exceeds JavaScript’s safe-integer range. This tool rejects it instead of presenting an apparently exact but rounded integer.
Where does this calculation run?
It runs locally in your browser. Enter plain numbers without currency symbols or thousands separators; use the same currency and measurement units throughout unless a converter explicitly asks for units.