I would give absolutely no value to the output from an online fit calculator. The seat tube length has no effect on fit at all, so that value is worthless. What better defines the vertical size of the frame is the head tube length, with the headset (not bare). The TT length provided means NOTHING without a seat tube angle to go with it. The TT length and STA work together to define a reach value. Steeper STAs increase the reach, for given TT length (yes, this is correct, not backwards like so many think).

The combined length of the TT and stem length being the same does NOT mean two bikes fit the same, unless the STA is also the same.

To get the CC calculator up to date, they need to list a specific STA and the HTL, with the headset. Otherewise, the average newb won't know that one brand's 52cm is the same as some other brand's 54 or 56.