Afraid to ask but need to know.

I am a newbe on this forum, but have posted some threads already as I explore adding a lift and new tires and wheels and asked for input. The replies have been very kind, as I have been searching many dozens of posts from others who have done what I am looking for to make sure it all fits. I keep running into the same questions, and of course I also ran into the wheel-size.com calculator and there was another one posted by Bob (Moderator) who make it easy for all to get your questions answered regarding if this or that will fit.
I thought I would be intimidated by the referenced calculators, but must tell all that it is actually very easy to match what you currently have in regards to tires and wheels with your prospective plans with a side-by-side comparison. It is all in metric but if you have a cheap caliper or tape with both U.S. and metric readouts, you can judge for yourself what will work. For example, I was surprised to learn that my 275-55x20 was actually 1.25" shorter in overall diameter than a 275-70x18 which I'm planning, so fitment would be no issue but I would gain the 42 mm (1.5/8") in rubber to fill out the wheelwell I was looking for. Kudos to you who have supplied these tools!