Take the Raven Advanced Matrices test and find out your score on the test. For example, assume your raw score on the test was a 26.
Determine your percentile rank in the Raven test. For example, according to one table published by the Prometheus Society, a score of 26 corresponds to a percentile rank of 75 for someone between the ages of 33 and 37. You may want to check multiple sources for this rank, as measurements from different sources may yield different rankings.
Find the area under the curve of a normal distribution (as IQ scores follow a normal distribution) that corresponds to a z-score (a statistical measure) of 0.75. According to a chart published by SoftStat, the relative frequency of this score is 0.2486.
Find the score that corresponds to the relative frequency of the z-score. For a normal distribution, the relative frequency 0.2486 corresponds to a value of 111. Therefore, a Raven Score of 26 would convert to an IQ of 111.