Because weight is calculated based on gravitational pull, it is impractical to determine the weight of a planet. For example, an object weighing 500 pounds on Earth weighs 465 pounds on Saturn because of the planets' different gravitational pulls. Thus, planets are compared by calculating their mass, which remains constant.
Scientists calculate the mass of Saturn to be 568,319,000,000 trillion tonnes, which is calculated from measurements of Saturn's volume and density. Saturn's volume is around 154 times greater than the Earth's, but it is only one-eighth as dense, so the mass of Saturn is 95.161 times greater than the mass of the Earth.