All the sizing guidelines try to leave some space between your body and the top tube of the bike. The French Fit concept essentially eliminates that gap as much as a person can stand. The ultimate limit is when the bar presses against the bones of your pelvis. To assess that you need to take your inseam and add that thickness of your shoes - that is the upper limit of your standover height.

Then you either need to build this frame or analyze it mathematically to see what the standover height will be.

Math-wise, you need to know the wheel radius, bottom bracket height, seat tube length (c-t), seat tube angle, and the top tube slope angle.