Currently, a full SAR measurement protocol based upon CEI or IEEE standard recommendations takes around a half day. There is a specific need for fast SAR assessment for post-production measurement and verification. In the literature, different approaches are exposed to reduce acquisition time. From the measurement of the electric field E(x, y, d) in a reference plane z=d, which can be chosen not especially where the SAR is maximum, it is possible to calculate the maximum electric field E(x,y,z) for another z positions, and then the PEAK SAR value considering the following simple relation. However, for the measurement of 1g-SAR and 10gSAR values, corresponding to 1cm3 and 10cm3cubic volumes respectively, it is necessary to know the electric field distribution. A solution consist in extrapolating for each measurement point, the electric field around the maximum and then to average to calculate SAR 1g and SAR 10g, but this method is long. To reduce the calculation time, the idea is to describe the electric field distribution by a Gaussian function. This allows reducing the number of data acquisition points, like any other extrapolation methods, but the main interest is to describe the electric field distribution with only three parameters: peak, average and variance values. In addition, it is possible to define a simple relation (linear or polynomial) to describe the shape of the electric field distribution (variance) according to the distance of the transmit antenna or the distance of the measurement plane within the phantom. This approach is validated by a theoretically approach based on simulation (FEKO software) with a dipole antenna and a flat phantom and with measurements using mobile phones.