An essentially symmetrical ratio decoder which covers all areas in both the positive and negative regions with only a small number of noted exceptions. Multiple boundaries were selected such that the positive and negative regions were symmetrical with only a small number of exceptions. Using these boundaries, an essentially symmetrical, unified ratio decoder was constructed using only about one-half of the integrated circuit real estate of conventional ratio decoder pairs. By decoding the sign bit from the ratio decoder adder, the ratio decoder recognizes the exceptional areas and handles them accordingly.