IQ Percentile Calculator
Convert an IQ score to an approximate percentile assuming a normal curve with mean 100.
Formula
z=(score−100)/SD; percentile=100×Φ(z), numerically approximated.
Model percentile ≈ 50+50×sqrt(1-exp(-(1)^2×(17+(1)^2)÷(26.694+2×(1)^2)))
How to use
- Enter the reported IQ score.
- Set the test standard deviation.
- Read the approximate percentile.
Examples
- IQ 115 with SD 15: about the 84.1st percentile.
Frequently asked questions
Does this measure IQ?
No. Enter a score from a valid assessment; 100 and SD 15 are model assumptions.
Is this the official test percentile?
No. Test norms, age and score ceilings may differ; use the publisher’s report.
Is this medical advice?
For reference only; it does not replace a clinician.
Sources
Updated: