Every brand sizes a little differently....don't go by the number. It's kinda like clothing....the number will get you close, but you may need to size up or down after trying it on. I don't place too much stock in the size, but focus more on the reach to the bars. For me and my short torso, that's the key dimension.

Have fun test riding!

P.S. At 5'4" with long arms and legs and a short torso, my bike size is anywhere between 46cm and 50cm, depending on the geometry.