Hey, just like Phukette suggested, stick to your regular size. The chi tights are a bit small around the knees, but that will stretch. The only problem is they don't have belt loops (if that's the right word) on the sides (only front and back), so the tighter the better since the waist stretches as well. A size smaller would be ok for the waist, but even my skinny legs won't fit then. I have size 30 for both Jeans and Chi Tights.
They're on sale now! So, lucky you
And JiNious, thank you!