spoiler
For people that don’t know this is not how you use Calipers
This just tells me calipers should have 2 measuring bars on them, so gaps and other inside edges can be measured like this (maybe this already exists, idak)
That’s what the two prongs at the top are for. Flip the caliper upside down, use the prongs to measure the inside dimension, and read it off the same scale.
“Caliper jaws for inside measurement—I thought of that. Turned out it already existed, but I arrived at it independently."
Next time, chose a smarter client.
A normal set of calipers has 3 basic modes of measuring things: inside, outside, and depth. It is amazing to me how many people in this thread don’t know at least one of those or use them wrong.