Background: Mach's Principle posits that the inertia of a body is inuenced by the sum total of matter in the universe. This paper explores the relationship between gravitational potential energy and rest mass within the framework of Mach's Principle, utilizing a thought experiment involving the elevation of mass on Earth.Methods: The study employs a theoretical approach, beginning with a thought experiment that demonstrates the change in an object's rest mass due to alterations in gravitational potential energy. Subsequently, a mathematical model is developed to express rest mass as a function of distance from a massive central body, incorporating adjustments for observed astronomical phenomena such as the precession of Mercury's orbit.Conclusion: The findings affirm the principle that an object's rest mass is influenced by the gravitational potential of all other masses in the universe, aligning with Mach's Principle. The study underscores the need for revisiting the definitions of fundamental units of measurement such as the second and the meter, in light of gravitational dependency. The implications for astronomical theories, including gravitational redshift and the assessment of quasar emissions, are discussed, suggesting a potential reevaluation of existing models.