Intraoperative surgical resection planning includes setting a cutting angle for a planned distal femur resection to provide a desired extension gap relation, automatically setting distal femur resection amounts for the planned distal femur resection such that a medial or lateral extension gam is within a threshold of a target, planning a femoral component rotation to provide a desired flexion gap relation, selecting a femoral component size based on flexing/extending a current planned femoral component, determining whether the desired extension gap relation is maintained, and performing processing based on whether the desired extension gap relation is maintained.