A grading control system for a machine, comprising: a lift actuator configured to selectively raise and lower the work implement (38, 64); a tilt actuator configured to tilt a work implement of the machine; a first sensor configured to communicate a first signal indicative of a first position of the work implement relative to at least one of a machine frame or a gravity vector; a second sensor configured to communicate a second signal indicative of a second position of the machine frame relative to the gravity vector; and a controller in communication with the first and second sensors and configured to: determine a track plane defined by an undercarriage of the machine; determine a desired grade relative to the track plane; determine an orientation of the work implement relative to the track plane required to maintain the desired grade based on at least one of the first and second signals; and generate at least one control signal to actuate at least one of the lift actuator and the tilt actuator to orient the work implement based on the determined orientation; wherein the machine includes: a loader joint between a lift arm associated with the work implement and the machine frame; and a tool joint between the work implement and the lift arm; characterised in that the controller is further configured to determine the orientation of the work implement based on a kinematic model of the machine; and wherein the kinematic model includes: a first virtual linkage extending between the tool joint and a ground surface; a second virtual linkage extending between the loader joint and the tool joint; and a third virtual linkage extending between the loader joint and an idler. a lift actuator configured to selectively raise and lower the work implement (38, 64); a tilt actuator configured to tilt a work implement of the machine; a first sensor configured to communicate a first signal indicative of a first position of the work implement relative to at least one of a machine frame or a gravity vector; a second sensor configured to communicate a second signal indicative of a second position of the machine frame relative to the gravity vector; and a controller in communication with the first and second sensors and configured to: determine a track plane defined by an undercarriage of the machine; determine a desired grade relative to the track plane; determine an orientation of the work implement relative to the track plane required to maintain the desired grade based on at least one of the first and second signals; and generate at least one control signal to actuate at least one of the lift actuator and the tilt actuator to orient the work implement based on the determined orientation; determine a track plane defined by an undercarriage of the machine; determine a desired grade relative to the track plane; determine an orientation of the work implement relative to the track plane required to maintain the desired grade based on at least one of the first and second signals; and generate at least one control signal to actuate at least one of the lift actuator and the tilt actuator to orient the work implement based on the determined orientation; wherein the machine includes: a loader joint between a lift arm associated with the work implement and the machine frame; and a tool joint between the work implement and the lift arm; characterised in that the controller is further configured to determine the orientation of the work implement based on a kinematic model of the machine; and wherein the kinematic model includes: a first virtual linkage extending between the tool joint and a ground surface; a second virtual linkage extending between the loader joint and the tool joint; and a third virtual linkage extending between the loader joint and an idler. a loader joint between a lift arm associated with the work implement and the machine frame; and a tool joint between the work implement and the lift arm; characterised in that the controller is further configured to determine the orientation of the work implement based on a kinematic model of the machine; and wherein the kinematic model includes: a first virtual linkage extending between the tool joint and a ground surface; a second virtual linkage extending between the loader joint and the tool joint; and a third virtual linkage extending between the loader joint and an idler. a first virtual linkage extending between the tool joint and a ground surface; a second virtual linkage extending between the loader joint and the tool joint; and a third virtual linkage extending between the loader joint and an idler.