Complex robots with multiple arms and sensors need good calibration to perform precise tasks in unstructured environments. The sensors must be calibrated both to the manipulators and to each other, since fused sensor data is often needed. We propose an extendable framework that combines measurements from the robot{\textquoteright}s various sensors (proprioceptive and external) to calibrate the robot{\textquoteright}s joint offsets and external sensor locations. Our approach is unique in that it accounts for sensor measurement uncertainties, thereby allowing sensors with very different error characteristics to be used side by side in the calibration. The framework is general enough to handle complex robots with kinematic components, including external sensors on kinematic chains. We validate the framework by implementing it on the Willow Garage PR2 robot, providing a significant improvement in the robot{\textquoteright}s calibration.