Contact lenses are generally defined by their power, base curve, and diameter.
Does anyone know how to calculate the sphere based on a base curve of 9?
Thanks for the help.

The base curve for contact lenses is the radius of the back side of the lens (see: https://en.wikipedia.org/wiki/Base_curve_radius). I'm not sure what you mean by "calculate the sphere," except to say that a sphere that matches a contact lens with a base curve radius of 9 would itself have a radius of 9 mm.