IQ Score 85: What Percentile Is Below Average?
An IQ score of 85, which is one standard deviation below the mean of 100, corresponds to approximately the 16th percentile.
How to use this tool
- Enter your test score.
- Enter the mean (average) score of the reference group.
- Enter the standard deviation of that group's scores.
- Read your z-score and percentile rank.
Calculate the percentile rank for an IQ score of 85, which sits one standard deviation below the population mean.
Frequently asked questions
- What does a percentile rank actually mean?
- If your percentile is 90, you scored at or above about 90% of the reference group. It is a relative measure of standing, not the percentage of questions you got right.
- Does this assume a normal distribution?
- Yes. The conversion uses the normal (bell) curve, which fits many large standardized tests well but can misstate percentiles for skewed or small-sample score sets.
- Where do I get the mean and standard deviation?
- From the test's published statistics or your class data. Many standardized tests publish a mean and standard deviation (for example, a mean of 100 with a standard deviation of 15).