I like roomy pjs so I got the 3X, normally a 2X when shopping at a store like Kohl's.  This 3X fits just fine, plenty of room fir tossing and turning.  Just one thing,  the top is a little short.  Not saying it's short.  Comes just below the bellybutton.  Another couple of inches would be perfect :)
Me:  5'3"/210#s .. so you have an idea regarding the sizing.