About Factorial Calculator
The Factorial Calculator computes the factorial of a non-negative integer, denoted as n!. The factorial of n is the product of all positive integers from 1 to n. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120. By definition, 0! equals 1.
Factorials are fundamental in combinatorics and probability. They calculate the number of ways to arrange n distinct objects (permutations), the number of possible orderings of a deck of cards, and binomial coefficients. Students use this tool to verify combinatorics homework and explore how factorials grow.
Developers encounter factorials in algorithm analysis, statistical computing, and machine learning. The gamma function extends factorials to non-integers, but for integer inputs, this tool provides exact results using standard arithmetic. It handles inputs up to 170, beyond which the result exceeds JavaScript's floating-point range.
The calculator is also useful for understanding exponential growth. Factorials grow faster than exponential functions — 10! is already over 3.6 million, and 20! exceeds 2 quintillion. This dramatic growth is why factorials appear in complexity analysis and why brute-force permutation algorithms become impractical for even modest inputs.
All computation happens locally in your browser. No data is uploaded, stored, or transmitted. The tool is free, requires no registration, and has no usage limits.
How to Use Factorial Calculator
Type or paste a non-negative integer into the input field.
The factorial result appears instantly below.
Click Copy to copy the result to your clipboard.
Values above 170 will show 'Infinity' due to floating-point limits.
Key Benefits
Frequently Asked Questions
What is a factorial?
The factorial of a non-negative integer n, written as n!, is the product of all positive integers from 1 to n. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120. By definition, 0! = 1.
What is the maximum input supported?
The tool supports inputs up to 170. Beyond that, the factorial exceeds JavaScript's floating-point range and the result becomes Infinity.
Can I calculate factorials of negative numbers?
No. Factorials are defined only for non-negative integers. The tool will display a message for negative inputs.
Is my number uploaded anywhere?
No. All computation happens entirely in your browser. Nothing is stored or transmitted.
Is the Factorial Calculator free?
Yes, it is completely free with no registration required.
Tips & Best Practices
Conclusion
The Factorial Calculator computes the factorial of any non-negative integer instantly, making it essential for combinatorics, probability, and algorithm analysis. Whether you're a student verifying homework or a developer analyzing algorithm complexity, this tool delivers exact results with one-click copying. Explore our related math and number tools for more resources.