IQ Score Chart and Scale
An IQ score chart translates scores into bands, percentiles, and plain-language ranges on a scale where 100 is average and 15 points is one standard deviation.
Key Takeaways
- Deviation IQ compares a person with same-age peers. Ratio IQ divided mental age by chronological age, an older method linked to William Stern.
- The bell curve helps show why scores near 100 are common and scores above 130 are rare.
- Use the lookup widget on this page to convert a score into an estimated percentile.
Score Context
This guide is part of the Rice Purity Hub IQ knowledge cluster. It explains the topic in plain language, uses standard psychometric terms, and links back to the free IQ test so readers can compare ideas with a private browser-scored estimate.
Limits And Clinical Use
IQ scores use a normal distribution with a mean of 100 and a standard deviation of 15. Percentiles describe how a score compares with a norm group, not a person's worth, creativity, kindness, or future.
How This Connects To The IQ Test
Online tests can be useful for self-reflection, but they are not clinical assessments. A licensed psychologist must administer instruments such as the WAIS, Stanford-Binet, or WISC when results affect diagnosis, placement, or accommodations.
Related Guides
FAQ
What is the key point of iq score chart and scale?
An IQ score chart translates scores into bands, percentiles, and plain-language ranges on a scale where 100 is average and 15 points is one standard deviation.
Is this page medical advice?
No. It is educational content and does not replace a licensed psychological assessment.
Can I take the free IQ test from here?
Yes. You can return to the free IQ test at any time and your answers are scored in your browser.