factorial calculator​

Factorial Calculator – Compute Factorials Instantly

This Factorial Calculator allows you to quickly calculate the factorial of any whole number. Whether you’re studying mathematics, working on computer science algorithms, solving probability problems, or checking homework solutions, this tool provides fast and accurate factorial results.

Simply enter a number, click “Calculate,” and the tool instantly displays the factorial value.

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What Is a Factorial?

A factorial (written as n!) represents the product of all positive integers from 1 to n.

Formula:

$$n! = n \times (n – 1) \times (n – 2) \times … \times 1$$n!=n×(n−1)×(n−2)×…×1

Examples:

• $3! = 3 \times 2 \times 1 = 6$3!=3×2×1=6
• $5! = 120$5!=120
• $7! = 5040$7!=5040

Factorials are widely used in:

• Probability and statistics
• Combinatorics
• Calculating permutations & combinations
• Programming
• Sequences & series
• Mathematical modeling

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How to Use the Factorial Calculator

1. Enter a non-negative whole number

Examples: 0, 1, 4, 10, 20, 50

2. Click “Calculate”

The calculator instantly computes the factorial.

3. View the result

Large numbers are displayed cleanly with full accuracy.

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Example Factorial Calculations

✔ Example 1: 0!

$$0! = 1$$0!=1

By definition, the factorial of zero is always 1.

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✔ Example 2: 5!

$$5! = 5 \times 4 \times 3 \times 2 \times 1 = 120$$5!=5×4×3×2×1=120

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✔ Example 3: 10!

$$10! = 3,628,800$$10!=3,628,800

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✔ Example 4: 20!

$$20! = 2,432,902,008,176,640,000$$20!=2,432,902,008,176,640,000

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Why Use This Factorial Calculator?

Ideal for:

• Students and teachers
• Programmers and developers
• Scientists and researchers
• Anyone working with permutations or combinations

Benefits:

✔ Instant and accurate calculations
✔ Supports values from 0 to 170
✔ Simple, clean interface
✔ Works on all devices
✔ No signup required
✔ Saves time on manual multiplying

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Frequently Asked Questions (FAQ)

1. What is the maximum supported input?

The calculator supports up to 170! — larger factorials exceed JavaScript numeric limits.

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2. Is 0! really equal to 1?

Yes. In mathematics, 0! = 1 by definition and is essential for combinatorics.

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3. Are decimals allowed?

No. Factorials are only defined for non-negative whole numbers.

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4. What fields use factorials?

They are used in:

• Combinatorics
• Probability
• Statistics
• Computer science
• Algebra
• Number theory

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5. Does this calculator show the full factorial value?

Yes — for all supported numbers, the full value is displayed.