I don't think giving someone just your height and asking about bike sizing is that easy. People are built differently and what works for one person may not work for another. I ride a WS 54 (not the same sizing as a men's 54) and I am just under 5'4. I test rode the 51 and kept moving the seat back to get comfortable to the point that there wasn't any further I could go back on the seat and still felt uncomfortable. I have a longer torso, and shorter legs. I ended up with the size up and got a shorter stem and it works perfect for me. I think you really need to go by what feels good for you. If you are really concerned with size, get a professional fit and then you can take your numbers and compare them to the bike specifications. All in all, you just need to go with what feels good.

good luck!!!