Factorial Calculator

Calculate factorials (n!) with detailed step-by-step solutions and explanations for any non-negative integer.

Enter Number

Number (n)

• Enter integers from 0 to 170

• Factorials grow very quickly!

Result

Enter a non-negative integer to calculate its factorial

Factorial Formula

n! = n × (n-1) × (n-2) × ... × 2 × 1

where n ≥ 0

Special case: 0! = 1

Examples

Small Factorials

0! = 1

1! = 1

2! = 2 × 1 = 2

3! = 3 × 2 × 1 = 6

4! = 4 × 3 × 2 × 1 = 24

5! = 5 × 4 × 3 × 2 × 1 = 120

Larger Factorials

6! = 720

7! = 5,040

8! = 40,320

9! = 362,880

10! = 3,628,800

15! ≈ 1.31 × 10¹²

Applications

Permutations

The number of ways to arrange n objects is n!

Combinations

Used in the formula C(n,r) = n! / (r!(n-r)!)

Probability

Calculating probabilities in various scenarios

Calculus

Taylor series expansions and other mathematical series

Frequently Asked Questions

A factorial of a non-negative integer n, denoted as n!, is the product of all positive integers less than or equal to n. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120.

Tips

Enter the dimensions in the same unit for consistency.
Results update automatically as you type.
Use the unit selector to convert between different measurement systems.

Factorial Calculator

Enter Number

Result

Factorial Formula

Examples

Small Factorials

Larger Factorials

Applications

Permutations

Combinations

Probability

Calculus

Frequently Asked Questions

Tips

Volume Calculators

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Factorial Calculator

Enter Number

Result

Factorial Formula

Examples

Small Factorials

Larger Factorials

Applications

Permutations

Combinations

Probability

Calculus

Frequently Asked Questions

Tips