A wide range of MR sequences produce inhomogeneous magnitude images due to the coil sensitivity variation over the head, which is especially severe for ultra-high field strengths. The optimum solution would be a homogeneous reference coil, which however is not possible at 7T due to the shorter wavelength. To date, correction methods require a very long computation time rendering them impractical for on-console imaging. We propose a new magnitude inhomogeneity correction approach, which is based on simplified segmentation and fast interpolation to estimate the bias field. The resulting images show high homogeneity across all three dimensions without any visible artifacts.