I’m 5′ 9" and weigh 123-124 lbs. I range from a size zero to four in dresses, but I’m a size 5 or 6 in pants. BUT i can also wear pants smaller than that if the hips are wide enough. How do hip waist and bust measurements work to determine clothing size and are dress and pants sizes interelated? I just want to know because I’m having trouble with catalogue/online shopping.