Context: Mixed dentition space analysis helps in determining the discrepancy between the available and required space in each dental arch during the mixed dentition period; further, it helps to diagnose and plan the treatment of developing malocclusion. Aim: The aim of this study is to evaluate the applicability of Tanaka and Johnston's and Moyer's methods of predicting the size of permanent canines and premolars and compare the tooth size between the right and left sides between males and females, and also to compare the predicted values of mesiodistal widths of permanent canines and premolars from Tanaka and Johnston and Moyer's method with the measured values. Materials and methods: The sample consisted of 58 sets of study models, of which 20 were girls and 38 were boys, that were collected from the children of the 12–15 year age-group. A digital vernier gauge, whose beaks were sharpened, was used to measure the mesiodistal widths of the individual teeth in order to increase accuracy. Statistical analysis: The two-tailed paired t-tests were used to assess the bilateral symmetry of the mesiodistal diameter of all measured individual teeth. Results and conclusion: It was concluded that Tanaka and Johnston's method could not accurately predict the mesiodistal widths of unerupted canines and premolars of children of Kanpur city due to the high variability in estimation, whereas the least statistically significant difference was obtained only at 65% level of Moyer's probability chart for male, female, and combined sample.