While moderate scoliosis is present in 1 in 300 children its effects on pulmonary compromise is not well understood. Severe skeletal malformations have been shown to result in decreased pulmonary function, lung development, pulmonary hypertension, right-sided heart failure, and premature mortality. Unfortunately, the degree and combination of deformity have not been studied for their specific effects on the space available for the lungs and the resulting pulmonary deficiency. The objective of this study is to develop and validate a computational model to measure thoracic volume of scoliosis, pectus, and combined deformity in order to predict cardiopulmonary function. Utilizing Blender software, we constructed a computational model of the spine and thorax which may be ‘computationally deformed’ to match chest X-rays and compute the resulting thoracic volume. The size and orientation of the individual bones of the spine and thorax are altered until they fit the x-ray projections of the patient, creating a patient-specific model. The thoracic volume was then computed by meshing the space within the thoracic cavity and these data were validated against CT reconstructions. The thoracic volumes measured for the scoliosis cases were on average 8.4 cc differentce between the methods with a maximum error of 3.8% and a mean error of 2.4%. We have developed a methodology for deforming a computational model to create a patient-specific skeletal thorax which can be used to measure thoracic volume for patients with spinal and thoracic deformity.