What your IQ percentile actually tells you
A percentile answers one question: what share of your reference group scored below you. It is the most readable part of any score report.
Where the number comes from
The percentile is read off the normal curve at your standard score. It is a property of the distribution, not a separate measurement, so it moves in lockstep with the IQ figure.
Why the middle is crowded
Half the population sits between 90 and 110. Ten points near the mean move you past far more people than ten points at the tail, which is why small score changes matter most in the middle.
Reading it without inflating it
A 95th percentile result means 5 in 100 of your norm group did as well or better. In a room of forty people that is two others, not none.
Scored against age, education and area norms. Free certificate with a QR code anyone can verify.
Questions people ask
Is percentile the same as percentage correct?
No. Percentile is your rank against other people; percentage correct is how much of the paper you solved.
Can two people with the same IQ have different percentiles?
Only if they were scored against different norm groups.