There are instances in which it is desirable to determine relationships among fruit physical attributes. For example, fruits are often graded on the basis of size and projected area, but it may be more economical to develop a machine which would grade by mass or volume. Therefore, the relationships between mass/volume (either mass or volume) and other physical attributes of fruit are needed. In this study three Iranian varieties of tangerine were selected and the various models for predicting mass/volume of tangerine from its dimensions, projected area, and volume/mass were established. The models were divided into three classifications: 1 – single and multiple variable regressions of tangerine dimensions, 2 – single and multiple variable regressions of projected areas, 3 – estimating tangerine mass/volume based on its volume/mass. The results revealed that mass and volume modelling on the basis of intermediate diameter, on any projected area, and the measured volume are the best models. Based on the results, mass and volume modelling, respectively on the basis of the actual volume and one projected area, were identified as the best models. The highest determination coefficient in all the models was obtained for volume modelling based on projected area as R2 = 0.97. Finally, volume modelling from economical stand-point was recommended as the most reliable modelling.