Disclosed is an system and method for determining a probability that a memory cell was programmed to a certain input level. An output level is received from a memory cell and a probability is determined that the output level corresponds to each of a plurality of programming levels. Each probability is determined as a function of the output level, a mean value of a distribution corresponding to the programming level, and a variance from the mean value with the variance being determined by a relative position of the output level with respect to the mean value. A probability value is generated as a function of the plurality of determined probabilities and then provided for use at a demodulator.