Because there is more gravity pulling you down than there is on Earth.
Jupiter
Jupiter, as it has the most gravity.
On Jupiter
A person would weigh the most on Jupiter, since Jupiter has the strongest gravitational pull. If it were possible to stand on Jupiter's liquid core, or swim in its liquid core, we could say that a person would weigh the most on Jupiter.However, since Jupiter is actually a gas planet, there technically is no "on Jupiter". Earth is the most massive terrestrial planet in the solar system, so a person would weigh more on Earth than "on" any other planet.In other stellar systems you would weigh more on Brown Dwarfs circling stellar companions. Despite their categorization, Brown Dwarfs do not have hydrogen fusion reactions inside their core, making them closer in resemblance to gas giant planets.
If you weigh 80 pounds on Earth, you would weigh approximately 212.8 pounds on Jupiter due to Jupiter's higher gravity.
You would weigh the most on Jupiter, the largest planet in our solar system. Its strong gravitational force, about 2.5 times that of Earth's, means that if you weigh 150 pounds on Earth, you would weigh approximately 375 pounds on Jupiter. However, keep in mind that Jupiter is a gas giant with no solid surface, so standing on it isn't possible.
On Jupiter, you'd weigh 83.07
On Jupiter, you'd weigh 292.50 pounds.
In our Solar System you would weigh the most on Jupiter. [See related link] On whatever planet weighs the most or has the most mass. For example the acceleration due to gravity is 9.8m/s on earth. On lets say the moon, it has a smaller mass therefore has a smaller acceleration due to gravity. So you would "weigh" less. On Jupiter , because weight of 110 LB (50 kg) on Earth will be 276.5 LB(125.5 kg) on the planet Jupiter.
If you weighed 100lb on Earth you would 236.4lb weigh on Jupiter
On Jupiter, they would weigh 585 pounds.
On Jupiter, you'd weigh 327.60 pounds.