Measure the circumference of an object

I feel like this must be so basic of a question but I am totally drawing a blank. I know I can use the ruler to draw the difference between two points, and I know I can get volume measurements by segmenting an object … but how can I get the circumference of an object? Ideally by “drawing” in the 3d view. Any ideas?

Draw a closed curve then see its length in the Markups module. Make sure you use a recent preview version.