As title indicates people need to know that the tp roll method is very flawed.

Below you will see 2 tp rolls that I have in my house that were bought from the same brand but 2 months apart.

I fit in the top one, technically anyone under 5.8" girth can. I don't in the bottom but people under 5.25" should be able to fit.

But I have seen pictures of smaller rolls on the internet as well like 4.25" in some markets. For reference the tube holder is about 1.5" circumference so the tube does not need to be > 4" but the companies increase the size of the tube to keep the outer diameter of the unused to roll big when they cut back on sheet count to save costs.

Inner Diameter