A method for branch metric calculation in a plurality of communications standards is disclosed. The method generally includes steps (A) to (C). Step (A) may calculate a plurality of sum values by adding a plurality of first values related to a plurality of information bits, a plurality of second values related to the information bits and a plurality of third values related to a plurality of parity bits. Step (B) may generate a plurality of permutated values by permutating the sum values based on a configuration signal. The configuration signal generally identifies a current one of the communications standards. Step (C) may generate a plurality of branch metrics values by adding pairs of the permutated values.