The preset count unweighted moving average (MA) algorithm for digital rate meters has been analyzed and compared to the preset count weighted MA algorithm. The correction factor applicable to the unweighted MA algorithm in order to obtain a final result identical to that of the weighted MA algorithm has been found. It is shown that the response time of the corrected unweighted MA algorithm to an increasing count rate is shorter than that of the weighted MA algorithm. This makes the corrected unweighted MA algorithm suitable for nuclear engineering applications where the slower response of this algorithm to a decreasing count rate need not be considered a shortcoming. The statistical fluctuations in a steady state of the unweighted MA algorithm are found to be somewhat higher than those of the weighted MA algorithm. However, this difference becomes negligibly small for a sufficiently high value of the preset count. (C) 1999 American Institute of Physics. [S0034-6748(99)02209-1].