Abstract: A method for calculating the Specific Absorption Rate (SAR) caused in a body by the electric field of a wireless communications device, and comprises using a model of said body. The device is placed in the proximity of the model, and the electric field is measured at discrete points. The method comprises measuring the magnitude of the electric field in points of a first and a second surface in the model. By means of the measured magnitudes, the phase in said points is determined, so that the complex electric field in said points is determined, and the complex electric field in said points is used to determine the complex electric field in said model. The complex electric field is used in order to calculate the SAR value caused by the device.