Turns out it way more complicated than that, but the formula still kinda works.
Those numbers are fine, start with them. To really fine tune it, slice up a large spiral vase 3d print, let the printer run for a while, then feel the steppers. They are doing pretty good when they are warm but not hot enough to melt the PLA. You need a file that keeps the motors constantly engaged, and moving, spiral vase is nice for that.
That is the super scientific method, wear a lab coat while doing it.