<p>Environmental change is altering habitat in lakes and reservoirs as surface warming and bottom-water deoxygenation compress vertical habitat for temperature sensitive species (oxythermal compression). While processes driving vertical habitat are understood, less clear is how shifts in depths of thermal and oxygen stressors translate into changes in habitable volume. Using a modeling exercise holding maximum depth and surface area constant, bathymetry strongly influenced habitable volume in response to vertical habitat compression. Shallow-sloped lakes were more vulnerable to surface downward losses and deep-basin lakes had greater relative sensitivity to bottom-up losses. When the upper thermal and lower oxygen boundaries were simultaneously shifted shallower by the same vertical distance, habitable volume increased by 6% in a deep-basin lake but by 58% in a shallow-sloped lake. A random subset of 100,000 waterbodies from the GLOBathy and HydroLAKES datasets indicated morphometries span the range characterized in this study, but tend to have a mean-to-maximum depth ratio of 0.25, like shallow-sloped lakes that have greater sensitivity to surface-down losses. These results show that equal vertical shifts in oxythermal habitat do not equal volumetric consequences, and that bathymetry is a key feature in understanding how vertical habitat changes translate to habitable volume.</p>