Mixing in the Kenics static mixer is optimized using computational analysis and theoretical concepts. A total of 54 cases were examined to consider the effect of mixer geometry and inertia on flow and mixing performance. The effect of varying the standard geometry is discussed for a broad range of Reynolds numbers. While only the twist angle affects performance at low flow rates (Re congruent to 1), both the element aspect ratio and the twist angle are shown to be important at high flow rates (Re less than or equal to 1, 000). The energetic mixing efficiency decreases with increasing flow rate. Finally, a quality-driven design method is developed based on stretching calculations, and is illustrated for the standard mixer design.