Math calculator
Factorial Calculator
Calculate n! and related combinatorial values.
About the factorial calculator
The factorial calculator computes n! for any non-negative integer up to 170.
How to use this calculator
- 1
Enter n
Enter a non-negative integer (0-170).
- 2
View results
See the factorial value.
How the calculation works
n! = n × (n−1) × ... × 1. 0! = 1.
Example: 5! = 120. 10! = 3,628,800.
When to use a calculator vs. mental math
Simple operations like percentages and proportions are great for mental math. Complex problems — quadratic equations, standard deviation, and base conversions — benefit from calculator precision. Always estimate the answer first to catch input errors, and verify results with a second method when possible.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about factorial calculator
How accurate is the factorial calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.