Glossary
Percentile
Definition
A percentile is the share of people in a reference group who score below a given score. An IQ at the 90th percentile is higher than about 90% of people the same age. It describes rank, so it runs from just above 0 to just below 100, never past them.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Why it matters for IQ scores
An IQ number only makes sense next to its percentile. Because IQ scores are standardized to a normal curve with mean 100 and standard deviation 15 (Wikipedia: Intelligence quotient), each score maps to exactly one percentile and back again. Percentiles are also scale-free: the 98th percentile means the same thing on every test, even when the printed IQ differs.
Examples
- IQ 100 is the 50th percentile: half of people score below it.
- IQ 110 is about the 74.8th percentile.
- IQ 125 is about the 95.2th percentile.
- The 98th percentile, the Mensa line (Mensa International), is about IQ 131.
Common confusions
Percentiles bunch up in the middle and stretch out in the tails. Moving from 100 to 110 crosses about 25 percentile points, while moving from 130 to 140 crosses only about 1.9. That is a property of the normal distribution, not a quirk of any test. To look up any rank, browse IQ by percentile, try the IQ percentile calculator, or read is an IQ score a percentage?
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 2 is the original figure turned a quarter turn clockwise.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a quarter turn clockwise gives option 2.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Sources
- Intelligence quotient. Wikipedia. en.wikipedia.org/wiki/Intelligence_quotient
- About us. Mensa International. www.mensa.org/mensa/about-us