May 25, 2026 9 minutes read

Cyclomatic Complexity (or CC ) in C# is a code metric that counts the number of linearly independent execution paths through a method. Concretely, it is computed as 1 plus the number of branching constructs in the method body (such as if , while , for , case , && , || , ?: and ?? ). The higher the score, the harder the method is to read, test and safely change. A score of 1 means a single straight path, around 10 is the traditional upper bound recommended by Thomas McCabe, and anything above 25 is flagged as excessive by Microsoft’s CA1502 analyzer.

This guide explains, with C# examples, how Cyclomatic Complexity is calculated, what thresholds matter in practice, how to measure and visualize it in real .NET codebases, and how to go beyond the raw score by pairing it with test coverage and IL-level analysis.

What is Cyclomatic Complexity?

Definition of Cyclomatic Complexity in C#

Example of Cyclomatic Complexity Impact in C# Exhibiting a Complex Method

Refactoring the Complex…