Developer Experience
Cyclomatic Complexity Calculator
Enter the number of decision points in a function to compute cyclomatic complexity, minimum test cases for full branch coverage, and refactoring recommendations.
No data is transmitted — everything runs locallyTool
Example — Function with 8 decision branches (CC = 9)
Complexity
9
Risk Level
Low
Recommended
≤10
About this tool
Cyclomatic Complexity Calculator
The Cyclomatic Complexity Calculator computes complexity from decision point count, shows minimum test cases for full branch coverage, and classifies complexity against standard thresholds.
• Calculate minimum test cases required for full branch coverage of a function
• Check whether a function's complexity exceeds the team's CI gate threshold
• Understand the relationship between cyclomatic complexity and testability
• Compare cyclomatic vs cognitive complexity for the same code
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FAQ
What does this tool tell you?
The Cyclomatic Complexity Calculator computes complexity from decision point count, shows minimum test cases for full branch coverage, and classifies complexity against standard thresholds.
What affects the result most?
Cyclomatic complexity = edges - nodes + 2 × connected_components, or simpler: decision_points + 1. Decision points: if, else if, for, while, do-while, switch case, catch, ternary (?:), logical && and ||. Complexity thresholds: 1-10 simple, 11-20 moderate, 21-50 complex, >50 untestable.
How should I use the result?
The calculation is deterministic — the same inputs always produce the same output — so the most useful workflow is to vary one input at a time and see which factor moves the result most. That tells you where to focus your attention before committing to a decision.
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