Golden axe just tells you the volume of blocks selected, not quite distance. However, you can use //size with a selection and it will give you position points, size, # blocks, and distance.
What I do whenever I need to measure a block distance is take the coords of each end and subtract the greater distance to the lesser one. You don't really need a complicated golden axe or a custome tape measure device if you have a calculator within reaching distance. Hell you are on a computer with an obvious Internet connection, just use the Google calculator. If in doubt consult Google.
Plz Lazuli. That's not even how humans function. We invent things to help us do more work with less effort. Coordinates often involve big numbers and you have to press a lot of buttons. Ideally this would require holding the item and right-clicking twice. //Size does work although it does require inputting commands every time and the results are messy. If nothing else is available it'll work, but my preference is having an actual item like the Bibliocraft mod has.