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Last updated: July 31, 2026

Gamma Function Calculator

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Formula

Γ(x) extends factorial: for integer n>0, Γ(n) = (n-1)!

Where:

  • x=x value
Gamma FunctionGamma of 5 equals 4 factorial, which equals 24, showing how Gamma extends the factorial function.Γ(5) = 4!=24Γ(n) = (n − 1)! for positive integers, and is defined for all reals except non-positive integers
The Gamma function generalizes the factorial to real (and complex) numbers.

Worked Examples

Integer relation

Evaluate Γ(6).

  1. 1Use Γ(n)=(n-1)!
  2. 2So Γ(6)=5!
  3. 35! = 120
Final Answer: value=120

Half-integer

Evaluate Γ(1/2).

  1. 1Known identity Γ(1/2)=√π
  2. 2Compute √π numerically
  3. 3Round to 6 decimals
Final Answer: value≈1.772454

Non-integer positive

Evaluate Γ(4.2).

  1. 1Apply Lanczos approximation
  2. 2Compute stable numerical value
  3. 3Round output
Final Answer: value≈7.75669

Introduction

The gamma function generalizes factorial to non-integer values and appears in probability, statistics, and physics.

Formula and Method

Gamma Function Calculator applies Γ(x) extends factorial: for integer n>0, Γ(n) = (n-1)! and returns deterministic outputs from validated inputs.

  • Validate each required input

  • Apply the stated formula

  • Round numeric outputs where needed

  • Return safe defaults when validation fails

Input Fields

Use these keys exactly as defined in calculation.ts.

  1. 1

    x: x value

Output Fields

These values map directly to calculation.ts return keys.

  1. 1

    value: Numerical approximation of Γ(x)

Validation Rules

Input must be finite, not a non-positive integer pole, and not above internal overflow guard.

  • Finite numeric values are required

  • Domain restrictions are enforced before solving

  • Invalid input returns default-safe outputs

  • Check examples to confirm expected behavior

How to Use This Calculator

Enter inputs, run the calculation, and read the primary output first.

  • Enter all required values

  • Click calculate

  • Review primary output first

  • Use supporting outputs for interpretation

Practical Uses

This calculator is useful for study, verification, and fast applied math checks.

  • Probability distributions

  • Advanced calculus

  • Special-function verification

  • Statistical modeling

FAQs

What does the Gamma Function Calculator compute?

It computes Gamma Value and supporting outputs from your inputs.

Which inputs are required?

Required inputs are: x value.

How are invalid inputs handled?

When validation fails, the calculator returns safe default values and does not attempt invalid math.

Are results rounded?

Yes. Numeric outputs are rounded inside calculation.ts (typically to 6 decimal places).

Can I use negative or decimal values?

Real finite values are supported except non-positive integers and values beyond the overflow guard.

How should I verify my answer?

Use the worked examples and compare each output key with your manual steps.