Calibration method to determine the complete Jones matrix of SLMs

•Spatial light modulators can implement phase and amplitude masks.•Spatial light modulators can show diattenuation.•Calibration of the complete Jones matrix of spatial light modulators.•Reduction in the error of expected transmission of spatial light modulators. We present a simple method to determine the polarimetric properties of spatial light modulators (SLMs) for each grey level by means of irradiance measurements. The Jones matrix of the SLM is obtained without any assumption about its properties, so it can be applied for more devices than previous works. This method is simple enough to be quickly performed, while offers better results than previous works, as it reduces the error in the prediction of transmission intensities in a factor between 5 and 380.