Mine is 34.5" I'm 5' 11". I currently am on a 56 cm Tarmac. I like a somewhat aggressive position it gives with a fair amount of drop from the saddle to the bars/hoods. I tried the 58cm model, but I felt it was not as sporty handling as I wanted and since frame stack increases with size I would be limiting how low I could go with the bars for me. Frame reach also increases with increasing size. Though that's only in general, you might find some exceptions. Older vintage bikes might scale the reach differently with size than newer bikes. But there is no one pat answer. You have to consider each model individually for size.

For my 2020 Tarmac, Specialized recommended either a 56 or a 58 cm frame. There are some models of bike I would be suggested a different size because of the differences in the geometry between the two models. So don't just blindly look for one particular size bike. You'll be frustrated when you get to the bikes that are letter sizes. <grin>

I use to ride a 59cm Raleigh Competition GS and a 60cm Schwinn Paramount. Before that a 25" (about 64cm) Schwinn Varsity. All comfortably.