Abstract: An invention is provided for spindle downforce calibration. The system includes a calibration wafer carrier having a calibration load cell recess, and a calibration load cell disposed within the calibration load cell recess. The system further includes a meter in communication with the calibration load cell. In operation, the calibration load cell measures a downward force applied to the to the calibration wafer carrier. The measurement can be taken when the calibration wafer carrier is positioned substantially at a polishing height, which is substantially equivalent to a height of a normal wafer carrier during a chemical mechanical polishing (CMP) operation. In one aspect, the measured downward force is compared to a tool downward force measurement that is measured using a tool load cell, which is generally utilized to measure tool downward force during a normal CMP process.