Yes, I'm a 14 in M&S and supposedly a 18 in big 4 patterns, though only with shoulder pads like an American footballer!
Going by measurements is essential and, more to the point, go by upper bust measurement and adjust for boobs as appropriate.
Then take into account that we're all a bit wonky. I was 5'4 10 years ago, no doubt less now as that was already an inch off my young adult height, yet I often need to add an inch or so to the body length of tops and the rise of trousers. See also, taking 2-3" off the inseam of trousers before I even try to square my flat arse and middle aged gut.