Cancer progression is linked to alterations in cellular energetics, where malignant cells reprogram their metabolism to sustain proliferation, resist stress and adapt to nutrient limitations. Beyond intrinsic adaptations and plastic dynamic switches between glycolysis and oxidative phosphorylation, recent work has shown that tumors actively remodel their microenvironment by acquiring functional mitochondria from surrounding stromal or immune cells. This process of mitochondrial transfer enhances tumor bioenergetics while simultaneously depleting immune cells of metabolic competence, thereby reinforcing both tumor growth and immune evasion. Despite the role of these mitochondrial exchanges, quantitative frameworks to measure their energetic consequences remain underdeveloped. Conventional assays describe oxygen consumption or glycolytic flux but lack the resolution to capture mitochondrial function in terms of throughput, efficiency and stored energy. To address this limitation, we propose a simulation-based framework that translates engineering-style energy metrics into mitochondrial biology. Specifically, we calculate three parameters that may capture distinct yet complementary aspects of mitochondrial bioenergetics: power density, defined as ATP production per unit mitochondrial volume; surface power density, reflecting ATP production per unit inner membrane area; and energy density, quantifying stored chemical free energy per unit volume. By simulating tumor and immune cell populations before and after mitochondrial transfer, we generate numerical values for each parameter that demonstrate how transfer enhances tumor energetics while diminishing immune function. This provisional quantification establishes a pathway toward standardized bioenergetic biomarkers in cancer, potentially enhancing diagnostic methods and supporting the development of strategies aimed at disrupting pathogenic mitochondrial transfer while restoring metabolic competence to immune cells.