Techniques are described to use a reference motion vector to reduce the amount of bits needed to encode motion vectors for inter prediction. One method includes identifying a candidate motion vector used to inter predict each of a plurality of previously coded blocks to define a plurality of candidate motion vectors, identifying a set of reconstructed pixel values corresponding to a set of previously coded pixels for the current block, and generating, using each candidate motion vector, a corresponding set of predicted values for the set of previously coded pixel values within each reference frame of a plurality of reference frames. A respective error value based on a difference between the set of reconstructed pixel values and each set of predicted values is used to select a reference motion vector from the candidate motion vectors that is used to encode the motion vector for the current block.