What is the easiest way to measure bread's rising? How can I easily measure the volume of my bread as it rises?  I usually eyeball it or test for feel, but this isn't very accurate, and definitely isn't getting the full rising potential out of it.

Proofing buckets seem like one possibility, but I don't want to buy a large uni-task kitchen item if possible.  I'm also not sure what volumes to expect from a pound of dough.
Do you have a large plastic container? Something like this:
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Use a non-permanent marker on the outside to mark the initial volume.

A small diameter will make it easier to monitor the volume.