A system for deploying and selectively inflating a thoracic aortic balloon at a desired location within the thoracic aorta for resuscitative aortic occlusion, inferior to the left subclavian artery, without the aid of fluoroscopy is described. Using CT imaging data, a distance between readily identifiable and consistently located external landmarks of torso extent is measured. Next, using the same data, a second distance from the femoral artery to a desired aortic occlusion location inferior to the left subclavian artery is determined. A correlation between the external measure of torso extent and the desired intra-arterial (i.e. endovascular) distance within the torso is made. Using a nomogram, a calibrated endovascular resuscitative thoracic aortic occlusion system can be positioned to this desired location on any injured individual with end-stage shock and impending cardiovascular collapse or death without the aid of fluoroscopy for delivery or balloon inflation.