It's hard to say for sure, but in general, a CX bike tend to be sized smaller then a road bike and the bars set are higher then a road bike.
For me, my C'dale CX frame is a 56cm compared to my CAAD7's 58cm. I also have the bars at the same level as the saddle on the CX bike, where as they are 3 or so inches below on the road bike. I also have the saddle about 2 cm lower and about 1 cm further back on the CX. I like to keep the reach a little shorter too. You're best bet is to talk to someone at the LBS for a fitting, and then dial it in as you go.