The Volume of a Capped Interior: Linear Growth in Mass Instead of Cubic Growth in Radius

For ten solar masses the capped volume is 2.046e-27 cubic metres against a horizon ball of 1.079e+14 cubic metres, a ratio of 1.896e-41. For a billion solar masses the capped volume reaches 2.046e-19 cubic metres yet the ratio falls to 1.896e-57. The capped volume grows linearly with mass while the horizon ball grows with the cube of mass, so the interior is, in this precise sense, mostly not at the cap: the ceiling governs a small central region and the rest of the interior lies at lower densities. This reframes the interior problem. Computed from stated assumptions, not measured.