Free tool
Percentile to IQ converter
Type a percentile to see the IQ score at that point on the three common scales: standard deviation 15, 16 and 24. Useful when a report gives a percentile, or when you want to compare scores from different tests.
Want your own percentile? The IQ Octopus test reports your estimated IQ and percentile together.
- IQ on an SD 15 scale
- 131Wechsler, Stanford-Binet 5 and most modern tests.
- IQ on an SD 16 scale
- 133Older Stanford-Binet forms.
- IQ on an SD 24 scale
- 149Cattell Culture Fair III.
- Classification
- Very SuperiorAbout 1 in 50 score this high or higher.
When to use this
- A report or school record gives a percentile rather than a score.
- You want to compare scores from tests that use different scales.
- You want to know what score sits at a threshold, such as the top 2%.
Three scales, one percentile
Most modern tests, including the Wechsler scales and the Stanford-Binet Fifth Edition, use a mean of 100 and a standard deviation of 15 (Wikipedia: Intelligence quotient). Older Stanford-Binet forms used 16, and the Cattell Culture Fair III scale uses 24 (Wikipedia: IQ classification). That is why Mensa UK lists a qualifying score of 148 on the Cattell III B and 132 on the Culture Fair test: both are the 98th percentile on their own scale (Mensa UK).
To go the other way, from a score to a percentile, use the IQ percentile calculator, or browse the IQ score chart.
Sources
- Intelligence quotient. Wikipedia. en.wikipedia.org/wiki/Intelligence_quotient
- IQ classification. Wikipedia. en.wikipedia.org/wiki/IQ_classification
- About us. Mensa International. www.mensa.org/mensa/about-us
- IQ tests. British Mensa. www.mensa.org.uk/iq-tests