100% free online Weight Converter tool. Use this tool to convert from one unit of measurement of weight to another. In science and engineering, the weight of an object is the force acting on the object due to gravity. The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton. For example, an object with a mass of one kilogram has a weight of about 9.8 newtons on the surface of the Earth, and about one-sixth as much on the Moon. Although weight and mass are scientifically distinct quantities, the terms are often confused with each other in everyday use (i.e. comparing and converting force weight in pounds to mass in kilograms and vice versa).
The introduction of Newton's laws of motion and the development of Newton's law of universal gravitation led to the considerable further development of the concept of weight. Weight became fundamentally separate from the mass. Mass was identified as a fundamental property of objects connected to their inertia, while weight became identified with the force of gravity on an object and therefore dependent on the context of the object. In particular, Newton considered weight to be relative to another object causing the gravitational pull, e.g. the weight of the Earth towards the Sun