Astronomer107 asked: "How can I figure out the g of a 10 solar mass black hole? If the sun is a certain "g" then can I multiply it by 10 to get the g of a 10 solar mass black hole?" Many people offered comment and suggestion but no one addressed this question. The radius of the event horizon of an ordinary (nonrotating uncharged) black hole is given by Schwarzschild's formula R = 2GM/c2 The acceleration of gravity at that radius is given by the classical formula GM/R2. This simplifies to c4/4GM. If you plug in values for c, G, and M, this will allow you to find out.