Rather than abandon reading expectancy formulae because they produce different reading expectancy scores, educators should attempt to improve such formulae in order to make appropriate decisions about students. Potential reading levels derived from the use of various expectancy formulae may be compared after converting the scores to stanines, which are more stable. Using a conversion method, seven reading expectancy formulae were tested with 161 elementary school students: 40 second graders, 48 fourth graders, and 73 sixth graders. A t-test was used to determine if the mean IQ scores of the sample were significantly different from the "normal" mean IQ of 100. The scores of both the second and fourth grade sample were significantly different, although the sixth grade scores were not. When classifying students as able or disabled readers, the Horn formula, the adapted Harris formula, and the Monroe formula were in agreement at least 90% of the time. At 70% agreement, the Gilliland and Carner formulae would also be acceptable. This study, previous studies, and clinical observation suggest the advisability of using the adapted Harris formula. (Tables and figures illustrate the text.) (JF)