How many calories does 8oz of de-fatted homemade chicken broth contain?
Homemade chicken stock can have a variety of densities, from being almost thick enough to cut into cubes at room temperature, to being a very thin broth, depending on the volume of chicken solids you used in making it, and how much you reduced it.   The variation is mostly going to be from gelatin.

With this level of variability, there is no reasonable way to give you a specific calorie estimate.

Live Strong estimates 75 calories per cup, but don't detail the nature of the stock they are assessing.  Still, this probably a good baseline; your product is probably in the 50-100 calorie per cup range.