The rapid adoption of renewable energy and energy storage technologies has accelerated the deployment of micro grids (MGs), highlighting the need for clear, standardized metrics to evaluate performance. Current definitions of several metrics for MGs vary widely, often ignoring key aspects such as internal losses, storage dynamics, and grid interactions, limiting comparability and practical applicability. This paper presents a comprehensive set of twelve well-defined metrics ranging from 0 to 1, which are inherently aligned with energy conservation principles and explicitly capture system losses. These generalized metrics serve as a framework for deriving use-case-specific metrics and framework-compliant equations. Synthetic yet realistic use case scenarios are used to demonstrate their flexibility and suitability for different technological and regulatory contexts. The results emphasize clarity, consistency, and practical relevance, laying the groundwork for broader empirical validation, standardization, and regulatory integration. Future work should focus on approximation methods to deal with real-world measurement limitations.