The ruler at the top and left of an Inkscape document can show up in different units, controlled in "Document Properties."
But regardless of what unit I choose (I'm using inches), the labels on the ruler are very small and hard to read on my screen, possibly because I'm using a 4K monitor. The rest of the interface, toolbar buttons, etc., are all fine but the ruler labels are about half the size I would want.
Here is a screenshot taken while at 1 to 1 scale (again, it's showing up large here because mine is a 4K monitor):
How can I make the labels bigger?