How strong is the gravity on Uranus? Although Uranus is much larger than Earth, its surface gravity is less than the surface gravity on Earth. This is because Uranus is made up of gases and is not solid like Earth. This makes Uranus very light for its size. The surface gravity on Uranus is about 86% of the surface gravity on Earth, so if you weigh 100 pounds on Earth, you would weigh 86 pounds on Uranus.