https://blendermarket.com/products/qol-gridcut

The GridCut addon is an elegant one-click solution for mesh slicing the current active object.    Many modifiers require meshes to have a certain polygon density, and the subdivide modifier very often, for many reasons, doesn't do the trick. Subdivide tends to cause gluts of tiny polygons, stretched polygons, and in the case of nGons, often bizarre tesselation. This is where GridCut comes in handy !  It evenly distributes cuts regardless of topology in any or all axes.