What is the effective top tube legnth?

I just recently started a similar post and stressed pretty heavily over a 56 or 58. My dimensions are extremely similar to yours. I'm 5ft 10.5 with a 34.5 inche inseam. What through me off the most was that I just looked big on it; I belive cause i'm kinda muscular up top.

Anyways, went with the 56 (which has a 56.5cm effective top tube) and I believe I made the correct decision. Not a Felt though, a Tarmac Comp.

hope this helps somewhat.

And i'm no expert; but you look fine on that size frame.