From the main Wiki entry on IQ tests: “The raw score of the norming sample is usually (rank order) transformed to a normal distribution with mean 100 and standa

From the main Wiki entry on IQ tests: “The raw score of the norming sample is usually (rank order) transformed to a normal distribution with mean 100 and standard deviation 15.” So, you’re not too far off numerically. 80 IQ is only a -1.33 Z-score. So, 9th percentile. 91% of people score higher than 80 IQ.