In the sagittal plane, the distal femoral condyles can be modeled using anterior and posterior circle segments. The aim of this study was to investigate how the radii of these segments vary with subject height. The MRI scans of 20 male and 20 female knees were analyzed with a computer to extract the radii of each condyle segment. These radii were then correlated with the patient's height. The anteromedial radii ranged from 22.6 to 32.6 mm. The posteromedial radii ranged from 15.4 to 26.3 mm. The anterolateral radii ranged from 19.7 to 30.4 mm. The posterolateral radii ranged from 15.2 to 23.6 mm. The radii had a strong correlation with patient height, with some differences between sexes. Linear regressions of the data yielded equations for estimating condyle radii from height. These radii estimations can be helpful in the clinical assessment of knee movement and treatment outcome.