It's really difficult.. Height 178, inseam 87 (measured at fitting shop, 86.5~6 measured at shop bike scale), but my arms aren't really that long.
I'm currently riding a 54 size, but the shop said my saddle was too low relative to my inseam, so they raised it by 2.5cm, and now the handlebar drop is enormous.
There's also been some increase due to the 165 crank.
It's not even a full cut. I'm planning to try changing to frame size 56.
I wish my arms were longer too. The fitting seems a bit tricky.