Factorial Calculator: Compute n! Up to 170 | Percentage Calculator

Factorial Calculator & Percentage Calculator Companion

Stuck on a homework problem with a giant factorial? Drop the number into our factorial calculator and get n! up to 170 instantly — no more wrestling with calculator overflow errors halfway through your stats assignment. Whether you're knee-deep in combinations and permutations, sketching out a probability tree before tomorrow's quiz, or double-checking a binomial expansion, this tool keeps the math out of your way so you can focus on actually learning the concepts. Pair it with our percentage calculator when you're juggling probability percentages, or jump over to the fraction calculator if your textbook still likes mixed numbers. Honestly, factorials sneak into more places than you'd expect — discrete

How to use Factorial Calculator & Percentage Calculator Companion

Type your number. Enter any whole number from 0 to 170 in the input field. Decimals and negatives won't fly here — factorials are defined for non-negative integers.
Hit calculate. Click the button (or just press Enter). The math happens instantly in your browser, so nothing gets sent off to a server.
Read the result. You'll see n! displayed in full. For bigger inputs the answer can get long — that's normal, factorials grow ridiculously fast.
Copy and reuse. Click to copy the output into your homework, lab notebook, or wherever you need it. Use it as a numerator or denominator for combinations and permutations.
Mind the 170 ceiling. 171! exceeds what standard floating-point math can hold without going to infinity, so we cap inputs at 170. If you need bigger, you'll want a symbolic math tool.

Frequently asked

Why does the calculator stop at 170?

171! is bigger than roughly 1.79 × 10^308, which is the maximum value an IEEE-754 double-precision float can store. Anything past 170 overflows to infinity, so we cap the input there to keep results reliable.

Can I enter a decimal or a negative number?

Nope. Factorial is only defined for non-negative integers. If you need the gamma function (factorial's continuous cousin), you'll need a more advanced tool.

What's 0! and why is it 1?

By convention, 0! = 1. It keeps formulas like nCr clean and matches the empty-product rule. Don't overthink it — just memorize it.

How do I use this for combinations or permutations?

For nCr, compute n!, r!, and (n-r)! separately, then plug them into n! ÷ (r!(n-r)!). The same trick works for nPr = n! ÷ (n-r)!. Super useful in probability problems.

Do you have other math tools on the site?

Yep — there's a standard deviation calculator for stats class, an area calculator for geometry, and a volume calculator for solids. Bookmark whichever ones match your current course load.

Is it actually free?

Free, no account, no email collection. The whole calculation runs in your browser, so it works offline once the page is loaded too.

Why are large factorials shown in scientific notation?

Once you pass roughly 22!, the digit count outgrows what most displays show comfortably. We switch to scientific notation so you can still read the magnitude at a glance.

Factorial Calculator & Percentage Calculator Companion

How to use Factorial Calculator & Percentage Calculator Companion

Frequently asked

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