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Code Complexity Analyzer

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Code Complexity Analyzer Guidelines

You’re one scan away from cleaner, simpler code.

Step-by-Step Usage

  • 1. Input Code: Paste your code or upload a file to begin analysis.
  • 2. Review Metrics: Examine Cyclomatic Complexity, Halstead Metrics, and Maintainability Index.
  • 3. Identify Issues: Pay attention to functions or modules with high complexity or effort.
  • 4. Use Suggestions: Follow edge-case insights and case study parallels for improvement ideas.
  • 5. Refactor: Split large functions, simplify logic, and reduce duplicated code.

Code Complexity Analyzer Description

What is Code Complexity?

Code complexity measures how difficult a codebase is to read, test, and maintain. Complex code often results in:

  • Increased likelihood of bugs
  • Longer development time
  • Higher maintenance costs

Key Metrics Used

Cyclomatic Complexity

Measures the number of independent paths through a program's source code.

Formula:

CC = E - N + 2P
  • E: Number of edges
  • N: Number of nodes
  • P: Number of connected components (usually 1)

Halstead Metrics

Based on the number of operators and operands in your code.

n1 = distinct operators
n2 = distinct operands
N1 = total operator occurrences
N2 = total operand occurrences

Vocabulary (n) = n1 + n2
Length (N) = N1 + N2
Volume (V) = N * log2(n)
Difficulty (D) = (n1 / 2) * (N2 / n2)
Effort (E) = D * V

Maintainability Index

A composite metric that considers complexity, volume, and code length.

MI = 171 - 5.2 * ln(V) - 0.23 * CC - 16.2 * ln(LOC)
  • V: Halstead Volume
  • CC: Cyclomatic Complexity
  • LOC: Lines of Code

Special Cases to Consider

  • Empty Functions: Still have a baseline complexity of 1.
  • Highly Nested Conditionals: Significantly inflate Cyclomatic Complexity.
  • Auto-generated Code: Often complex but may not need refactoring if not edited manually.
  • Operator-Dense Snippets: Small functions can still have high Halstead Effort.
  • Dead Code: May affect metrics even if never executed.

Mini Case Studies

Banking System API

A critical method in a financial API reached a complexity score of 36. Refactoring into smaller, focused functions reduced the score to < 10 per method and lowered post-deployment bugs by 40%.

IoT Device Firmware

Embedded code with low branching but intense bitwise logic showed high Halstead Effort. Modularizing improved readability and onboarding time by 30%.

Start analyzing your code now to improve quality, reduce bugs, and ship with confidence!

Example Calculation

MetricFormulaSample Values
Cyclomatic ComplexityCC = E - N + 2PE = 15, N = 12, P = 1 → CC = 5
Halstead VolumeV = N * log2(n)n = 20, N = 100 → V ≈ 432.2
Halstead DifficultyD = (n1 / 2) * (N2 / n2)n1 = 10, N2 = 60, n2 = 8 → D = 37.5
Maintainability IndexMI = 171 - 5.2 * ln(V) - 0.23 * CC - 16.2 * ln(LOC)V = 432.2, CC = 5, LOC = 200 → MI ≈ 65

Frequently Asked Questions

Code complexity refers to how difficult it is to understand, maintain, and modify code.

It's measured using metrics like cyclomatic complexity and Halstead complexity.

A cyclomatic complexity above 10 is often considered high. Above 20 is a critical threshold that warrants immediate refactoring.

Yes, as long as the structural analysis of your code (control flow and tokens) can be parsed, most languages are supported.

Maintainability Index also considers Halstead Volume and lines of code. A bloated function with low branching may still be difficult to maintain.

No, complexity analysis doesn't evaluate correctness—only structural and syntactic characteristics that may lead to risk.

Cyclomatic complexity is highly correlated with testing effort and bugs. Keeping it under 10 per function is widely recommended.

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