IQ Percentile Calculator

Use the IQ Percentile Calculator to convert an IQ score into a percentile using a normal distribution with mean 100 and standard deviation 15.

1.1M uses Updated · 2026-05-25 Runs locally · zero upload
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How to Use IQ Percentile Calculator

The IQ Percentile Calculator focuses on how to convert an IQ score into a percentile using a normal distribution with mean 100 and standard deviation 15. Follow these steps:

  1. Enter an IQ score from a test scaled with mean 100 and standard deviation 15
  2. The calculator standardizes the score into a z score
  3. Read the percentile as the estimated share of the reference distribution below that score

Formula & Theory — IQ Percentile Calculator

The IQ Percentile Calculator uses the following calculation logic:

z = (IQ − 100) / 15
IQ percentile = normal CDF(z) × 100

The IQ Percentile Calculator assumes the common IQ scale where 100 is average and 15 is one standard deviation. A score of 100 maps to the 50th percentile; higher or lower scores move symmetrically through the normal curve.

Use Cases for IQ Percentile Calculator

The IQ Percentile Calculator is most useful in these situations:

  • Statistics lessons on z scores and normal distributions.
  • Psychometrics examples where a standard score must be explained as a percentile.
  • Quickly translating an IQ score into a more intuitive rank-style measure.

Frequently asked questions about IQ Percentile Calculator

What does IQ Percentile Calculator calculate?

It helps convert an IQ score into a percentile using a normal distribution with mean 100 and standard deviation 15.

Are the formulas shown on the page?

Yes. The calculation formula is shown in a code block in the Formula & Theory section.

Is my data stored?

No. All calculations happen in your browser; nothing is sent to a server.