This paper presents two low complexity macroblock-level MAD (Mean Absolute Difference) prediction algorithms for H.264/AVC rate control. Both of the algorithms consider the rate-distortion performance and its hardware cost jointly. One of the algorithms predicts the MAD value by observing the motion vector of the surrounding macroblocks (MB), the other one uses numerical analysis to find the best fit weighting factors for the MAD value. These algorithms do not suffer from the MB-pipeline problems which decrease the rate-distortion performance, thus they are suitable for H.264/AVC hardware encoders. Experimental results show that the proposed MAD prediction algorithm can further improve the rate-distortion performance for the rate control scheme. Compared with the JVT-G012 rate control scheme, our algorithms can increase the PSNR to 0.38 dB and 0.35 dB, respectively.