I think I can usually have a guess at someone's class if they're middle - upper middle or upper class. Cannot tell the difference between working and lower middle class.
I still don't know which I am meant to be! Suspect LMC. But I don't have any if the Live, Laugh, Love signs, a particularly matchy house, say toilet or lounge...
I think I probably come from a wealthy enough family that I aspire to middle middle, despite my dad definitely being working class, but I wonder if that's because I grew up in a part of the UK where money goes further, so my dad's pretty good salary went miles. We had a big, Victorian villa, looking over the sea, with a big garden etc.
Now I'm in a modern mid terrace with a postage stamp sized garden. If you want a characterful, non matchy, detached house where we now live, (near london), you would need to be really quite wealthy imo.
So, I think class can change depending on where you live as well as between generations. If we lived where I grew up, with the same income as we have here, we would have the trappings of being more middle class I think. I wouldn't trade in a hundred years though. I love being near London and would take working class where I want to live over middle class where I don't.