Gravity Calculator for Astronomical Bodies Based on Radius and Density Gravity Calculator for Astronomical Bodies Based on Radius and Density Radius of the body: km (kilometers) Average density of the body: g/cc (grams per cubic centimeter) kg/m^3 (kilograms per cubic meter) (You can look up densities of materials here.) Note: When comparing the density of actual materials to the average density of the body, remember that a material at the core of a body could be denser than normal due to pressure from the weight of the surrounding material. Acceleration due to gravity at the surface of the body: m/s2 (meters per second per second) g (Earth gravities)
