The increasing thickening capacity in an inclined continuous thickener was theoretically analyzed by use of vertical and inclined solid flux curves obtained from vertical and inclined batch settling experiments with different calcium carbonate slurries. The model proposed in this study, which has a wedge-shaped layer of clear liquid developed at the upper surface of the inclined plate, can explain the difference between vertical and inclined settling velocities. Using these curves, the capacity of the thickener can be predicted based on graphical analysis of the critical loading operation under steady-state conditions. The capacity predicted by this analysis closely coincides with the results of experiments with the calcium carbonate slurry. Consequently, this procedure clearly provides an approach for analysis of an inclined continuous thickener, and also shows that the increasing thickening capacity for a thickener of any arbitrary vertical height can be determined graphically.