Re: When you say "pants",
Shoes are worse ... Different manufacturers use different sized lasts. And plants on different continents belonging to the same manufacturer use different sized lasts. The only the only good way to purchase shoes is to physically try them on.
Once when I bought "walking the dawgs" shoes, I tried on four identically labeled pairs. Same manufacturer, make, model, size and Universal Product Code. One pair was too small, one too big, and two fit as perfectly as off-the-shelf shoes ever do. I bought the two. They were made in Mexico, the large pair was made in Malaysia, and the small pair was made in Taiwan. Caveat emptor.