A magnetic field sensor includes a first magnetic field sensing element first generating a first signal having a first axis of maximum sensitivity, a second magnetic field sensing element for generating a second signal and having a second axis of maximum sensitivity, one or more detectors for receiving an output of the first magnetic field sensing element or the second magnetic field sensing element, and a processor that receives an output of the one or more detectors and uses the output of the one or more detectors to calculate a first constant Kc and a second constant Ks and then uses Kc and Ks to compensate for an orthogonality error between the first axis of maximum sensitivity and second axis of maximum sensitivity. The detectors include peak detectors and/or zero-crossing detectors that compare the output of the first input signal or the second input signal with a threshold or zero.