The Newtonian constant of gravitation denoted by letter G, is an empirical physical constant involved in the calculation(s) of gravitational force between two bodies . It usually appears in Sir Isaac Newton's law of universal gravitation, and in Albert Einstein's theory of general relativity. The constant is expressed in SI units, Newton meters squared per kilogram per second squared.
The Force of Gravity is a function of the mass of two objects (e.g. you and the Earth) and the distance between them. The gravity from the mass of the Earth is pulling on the mass in you and on any other object near the Earth. The formula for the the Force of Gravity is: