Factorial Calculator
Compute n! for any non-negative integer. Uses BigInt for exact values up to n = 10000 (digits in the thousands). Larger n uses Stirling approximation. Convention: 0! = 1.
What powers the Factorial Calculator
Exact BigInt up to n = 10000
Stirling approximation beyond
Digit count
0! = 1 convention
Why the Factorial Calculator is different
Browser-native
The Factorial Calculator runs entirely in your browser. Input is processed locally — never uploaded, never logged, never cached anywhere outside your device.
No artificial limits
No daily quotas, no character ceilings, no "upgrade for more" walls. Every feature is the complete feature — the same on the first use as the thousandth.
Production-grade quality
Built to the same engineering bar as paid SaaS tools — accurate algorithms, audited logic, responsive design and accessibility-tested interactions.
Common use contexts
- Combinatorics / permutations
- Probability computation
- Statistics / Poisson
- Computer science theory
Private and secure
Zero upload
All processing happens in your browser. Input is never transmitted, logged or cached.
Works offline
Once the page loads, the tool runs without an internet connection. No network calls happen during use.
No tracking
No accounts, no cookies for tool state. Only aggregate analytics count visits at the page level.