Quality Assurance (QA) is a vital component of the Software Development Life Cycle, aimed at detecting defects early and reducing their future occurrence. QA metrics, which can be base or calculated, are essential for measuring the testing process's effectiveness and product quality. Base metrics involve straightforward data points like the number of test cases or defects, while calculated metrics offer deeper insights into process efficiency and include process metrics and product metrics. Process metrics help track activities such as test tracking and execution productivity, while product metrics assess the software's effectiveness through error discovery and defect severity. Choosing the right metrics, such as Mean Time to Detect and Test Coverage, is crucial for improving QA processes and aligning them with business goals, ultimately ensuring fewer bugs in production. By leveraging these metrics, stakeholders can enhance team productivity, project estimation, and test coverage, contributing to the overall quality of software development.