Background <p>The septal cartilage is the most common and advantageous donor site for autogenous cartilage grafts in rhinoplasty.</p> Objectives <p>We aimed to examine the parts of nasal septum of Turkish patients and assess the association between the size of these structures and patient characteristics such as age and sex. Through this, we investigated whether some external features of the nose could be useful in predicting the septal cartilage area (SCA).</p> Methods <p>Paranasal sinus computerized tomography (PNCT) images of 174 patients were examined with Radiant Dicom Viewer 2024.1. The "multiplanar reconstructions" feature was used, and the coronal and transverse planes were adjusted to show the largest part of the septum in the sagittal plane. SCA, perpendicular plate of ethmoid (PPE) and Vomer areas were measured with the closed polygon area measurement feature.</p> Results <p>The mean SCA, PPE, Vomer, and total septal area (TSA) were 9.76 ± 1.89, 11.21 ± 2.23, 6.73 ± 1.26, and 27.72 ± 3.47&#xa0;cm² in overall, 10.26 ± 1.94, 12.33 ± 1.86, 7.26 ± 1.31, and 29.86 ± 2.88&#xa0;cm² in males, and 9.29 ± 1.74, 10.11 ± 1.98, 6.24 ± 1.01, and 25.15 ± 2.65&#xa0;cm² in females, respectively (<i>p</i> = 0.001, 0.000, 0.000, 0.000, respectively). SCA was negatively correlated with age and positively correlated with nasal bone length, nose projection, nose length, and TSA.</p> Conclusions <p>Greater age, female sex and small nasal pyramid are associated with smaller septal cartilage. CT is a reliable and useful method for evaluating the preoperative septal cartilage area.</p> Level of Evidence IV <p>This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors <a href="http://www.springer.com/00266">www.springer.com/00266</a>.</p>