How Do I Determine 'Scrub Radius' Of A Car's Wheels?

You would seem to have a computer, you shouldn't need to ask such stupid questions.

Heron:

You think I would have posted before searching? "make, model" and "scrub radius"

That's why I came here.

Well you certainly didn't perform a competent search.

Draw a line through the ball joint centers and through the center of the tires contact patch. Where they intersect upon touching the pavement shows the scrub radius. However it isn't quite that simple as it changes with ride height, tire flex and anything else that changes the tire location or size. Alignment, rim offset, tire size, tire inflation, any weight changes in the vehicle parts wear, all can change it.