At a rough guess I would say 10mm. I guess I wion't know unless I get them on the car... and I'm a bit reluctant to do that now. I might have to get under the car (as it is) and measure from where the calipers bolt on to the suspension and then to the inside edge of the wheel (for a bit more accuracy.)
They are wide and bl00dy heavy too!
if you fitted the seat sport calipers you wouldnt regret it there awesome brakes.
ive just measured from the outside edge of my disc to the outside edge of the calliper which is about 60mms,so if im right in thinking your standard discs are the same width as the cupra discs that should help you out i also measured the gap between the calliper and the wheel which is about 4mm.