About the IQ Score Percentile Calculator
What is the IQ Score Percentile Calculator?
IQ scores are standardised so the average is 100. This IQ percentile calculator shows what share of people score below a given IQ and how rare the score is.
Choose the test scale, because different tests use different standard deviations.
How to use the IQ Score Percentile Calculator
- IQ Score (sample: 115)
- Test Scale (sample: Wechsler / most modern tests (SD 15))
- Press Find IQ Percentile (results also refresh as you type). The result card shows the Percentile, along with Classification (Wechsler), Rarity, Z-score and Note.
Formula used
Percentile = Φ((IQ − 100) ÷ SD)
- SD = 15 for Wechsler and most modern tests
Online quizzes are not valid IQ tests.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| IQ Score | 115 |
| Test Scale | Wechsler / most modern tests (SD 15) |
| Result | Value |
|---|---|
| Percentile | 84.13% |
| Classification (Wechsler) | High average |
| Rarity | 1 in 6 people score this high |
| Z-score | 1 |
| Note | Only a professionally administered test gives a valid IQ score |
Tips for using the IQ Score Percentile Calculator
- IQ is only one measure of ability; it misses creativity and practical skills.
- Scores can vary by several points between test sessions.