Factorial Calculator
Calculate the factorial of any non-negative integer instantly, useful for permutations and probability, free in your browser.
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How to use this calculator
- Enter a whole number.
- Press Calculate.
How it works
n! multiplies all whole numbers from 1 to n. Used in probability and combinatorics.
Worked example
5!. = 5 × 4 × 3 × 2 × 1 = 120.
Frequently asked questions
What is 0! (zero factorial)?
It equals 1 by definition — there's exactly one way to arrange nothing.
Why do factorials get huge so fast?
Each step multiplies by the next whole number, so values grow faster than any power — 10! is already 3,628,800.
Related tools
- Permutations Calculator
- Combinations Calculator
- Combinations with Repetition Calculator
- Permutations with Repetition Calculator
- Arithmetic Sequence Calculator
- Average (Mean) Calculator
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Cite this tool
Zerdly. (2026). Factorial Calculator. Retrieved from https://www.zerdly.com/tools/factorial-calculator/
Tip: Enter any known values to calculate the remaining results.
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