I guessed and missed. Now that I use plastic rising buckets, I usually pat the dough into the bottom, note where the lines are, and wait for it to double. For years I avoided using rising buckets, since I have so many lovely ceramic bowls, but the bowls take heat away from the dough in the winter, and the bowls need to be covered with plastic wrap, although I did acquire some bread “shower caps” from KAF, and some German plastic discs that can cover the bowls. Once I started using the plastic dough buckets, I had to admit that they are better for letting dough rise, and I don’t waste saran, which is good for my wallet and the environment.
I got it, but I had to remember the formula for the volume of a sphere and do some math before I found the answer. I’m not at all exact in letting my dough rise. I normally let rise until it feels soft but normally punch it down before it gets near double.