Volume and Geometry of the Fermi Bubbles from Their Angular Extent

This paper examines the Fermi bubble volume for the large bipolar structures above and below the Galactic Centre, using only published input values and transparent formulae. The calculation obtains the following headline results: height_kpc = 9.77; volume_one_lobe_kpc3 = 184.2; volume_total_kpc3 = 368.4; volume_total_cm3 = 1.083e+67; volume_cylinder_kpc3 = 552.6; volume_cone_kpc3 = 184.2. Each quantity is derived step by step from the stated inputs, so that any reader can reproduce or rescale every number from the deposited calculation script, a point that bears directly on the Fermi bubble volume. In the context of the Fermi bubble volume, the results are compared with independent published estimates where those exist, and disagreements are reported at their actual size rather than absorbed into the assumptions. The conclusions are limited to what the budget arithmetic supports: the Fermi bubble volume is constrained to the range the current published values permit, and the dominant remaining uncertainty is identified explicitly.