Back in my university days I was a size 14, just an normal sized woman for my height. It was no problem going to a store and getting clothes, and if I wanted something a bit different I sewed it myself from a standard dressmaking pattern. The only problem was the average woman was supposed to be 5' 5" and as I am taller, the arms and legs tended to be a bit too short. I learned to live with that.
Over the years an interesting thing happened. I gradually put on a couple inches all round, top, middle and bottom - BUT, according to the labels I was still a size 14! it wasn't till my waist got to 33" that I went up to a 16. I suspected the manufacturers of becoming more generous in their cut as the Western world's waistlines expanded.
Having now dropped some weight I was looking forward to getting back into smaller clothes. I did a quick googol to see what I should be now. Oh me! I couldn't decide if I was an old size 14, a size 10, or, if I wanted to go to Europe; a British size 16, a Spanish 38 or an Italian 42. The entire system, it seems, has gone nuts, with each company deciding for themselves what they will label their clothes - except they are all trying to one up each other by flattering the consumer they fit the smallest size. There is even a size 0!! Round here the only people with a chance of squeezing into that are tiny Asian students.
Being accustomed to thrift store shopping and being a bit conservative in my taste, I hadn't quite caught up with this. But one I started looking I realized the labels were actually no help at all. One labels Petite fitted me quite well; another's Large was far too tight. I even found a skirt boldly labelled 28" waist that fitted my 31" waist very nicely thank you. I now realize why I'd so often grabbed a bag full of size 16s, only to find they didn't fit me at home - previously I thought they'd shrunk in the wash. Grr, the money I've wasted. I'll never buy without trying again.
In the end I got a size 6 jacket, a size 14 pair of pants, and several blouses in 8-10 sizes. All for $2. Iterestingly, they all looked as if they'd never been worn. Maybe somebody else has the same sizing problem?