No, you're measuring correctly ~ it's just that we are all different. Last time I measured, a couple weeks ago, I was 48.5/38/50. For clothing sizes, you're fitted at a combination of all three measurements (bust-waist-hip), not just waist. I'm an 18W pant/14-16-0X top at Catherine's/Lane Bryant and an 18 top/20 pant in misses stuff. I'm on the tall side of average but I am also very big-boned, with a lot of muscle tone, so clothes fit accordingly. I can't order clothes online ~ I have to try everything on.