A method of conditioning a CMP polishing pad to attain a desired thickness profile in a polished layer on a wafer is disclosed. The incoming thickness profile of the layer to be polished, the thickness profile of the polishing pad, a polish rate of layer as a function of pressure and the removal rate of polishing pad material by a conditioning block are used to compute a sweep pattern for the conditioning block which will produce a desired thickness profile on the polishing pad. The method may be applied to maintaining the desired profile on the polishing pad during the course of polishing multiple wafers. The pad profile may be adjusted to keep pressure between the pad and the wafer to a safe limit to reduce polishing defects.