The planet Jupiter is about 300 times as massive as Earth, but an object on its surface would weigh only 2.5 times as much as it would on Earth. Why?
The surface gravity depends upon 2 things. One its mass and the second id the distance from center.
As the density of Jupiter is onlu 1.32 g/cm Cube the distance from center will be high. Earths density is high 5.51 gm/Cm cube.
THat is the reason for low surface f gravity forula for calculating g=G *m/r 2.