How tall should bed risers be for under-bed storage?

Across r/college, r/UMD, and r/GERD discussions, 5–8 inches is the sweet spot for fitting standard under-bed bins or suitcases, while 12-inch dorm-style risers are recommended when you need to clear tall storage drawers or fit a mini-fridge underneath. Reviewers note that the taller you stack, the more lateral wobble you should expect.