My bikes are all 57-58ish cm and I'm 5'9" tall, in the morning, on a good day. FWIW my pants inseam is 30" so I don't think my legs are disproportionately long. I feel cramped on a frame much smaller than 57cm. Oh, and all my seatposts have a good fistfull plus showing. I don't recommend bike sizing over the internet. Ride the size that feels right to you. Allow several days or weeks of riding to home in on the right adjustments of stem, saddle, seat post, and handlebar angle. Don't hesitate to swap in a taller seat post, taller/longer/shorter stem, and/or different size/shape handlebar if you reach a physical adjustment limit with what you have.