A theoretical and experimental study was made of the conveying speed with which granular materials are transported by vibratory conveyors. The basic assumption made is that the layer of granular material can be considered as a point mass. The theory incorporates rest, slide, and flight phases of the material. Although the emphasis of this study is on the effect of the inclination (and declination) of the conveyor on the conveying speed, the effects of throw number, friction coefficient and vibration angle on the conveying speed are also shown. A useful method is presented for measuring the coefficient of friction between granular material and vibratory conveyor. Experiments were performed in order to verify the point mass theory. The agreement between theory and experiment is fairly good for slide conveyors but for throw conveyors larger deviations are observed. Some possibilities for improvement to the theory are briefly investigated.