So I've been creating a realistic solar system for something I'm writing. I thought I had created a decent planet like Earth, but once again my calculations were off and it had a g-force higher than that of Jupiter. As I emailed my friend: " just rechecked some calculations, and Aurrera is so effed up it isn't even funny. With that density and the radius, it would have a g-force higher than that of Jupiter. And if I kept the original g-force and density, it would have to be approximately 610,000 Km in diameter, or 52.63 times larger than Earth. So I need to rethink this. If we were to keep the radius and g-force, the density would be 2145.329 Kg/m^3, but that's about 2x less dense than the Earth. SO COMPLICATED!!! Well, let's see. If D = M/V, then 6442.951 = M / V And if M = 7.54113967 x 10^24, then 6442.951 * V = 7.5113967 x 10^24 Which gives V = 1.170448087 x 10^21 And if V = 4(pi)(radius^2) (1.170448087 x 10^21) / 4(pi) = radius^2 9.192677776 x 10^20 = radius^2 3.031942904 x 10^10 = radius (m) dividing by 1000 to give Km gives us 30319429.04 Km radius I'm so friggin' lost it's painful..." Any help? I still want that density and a reasonable g-force, but I think I'm going to have to have a different diameter. Here's the equation for g force in m/s^2: g = GM / r^2 where g is the gravity of the planet at the surface in m/s^2 G is the gravitational constant: 6.67x10^-11 M is the mass of the planet/object in kg, and r is the distance from the body (radius) in m EDIT: The density I wanted was 6442.951 Kg/m^3, since the planet would be rich in heavy materials like metals. The g-force should be between 0.9 g's (8.838 m/s^2) and 1.5 g's (14.73 m/s^2)