Citrus, yes. It all depends on the store and brand. And of course the fabric and cut. It's called vanity sizing.

In NY&CO, an XL top is slightly tight. Yet I have shirts in my closet from Ann Taylor LOFT that are a size medium, and fit almost perfect. Same with the pants. A 14 in NY&CO is camel toe tight, but the 14p in ATL is perfect right now.