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IQ Score Percentile Converter
Convert a reported IQ-style score into percentile and z-score terms using the selected scale mean and standard deviation.
⚠️ Note: This page converts an already reported IQ-style score into percentile terms. It does not measure intelligence or produce an official test result. Scores are influenced by the original test, norms, language, education, health, and testing conditions.
Age is not entered here because a reported IQ-style score is usually already age-normed in the original test report. Use the original report for age-specific interpretation and confidence intervals.
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7085100115130
IQ Score Percentile
84.1th
Above Average Range
IQ 115 (SD=15)
How common is this score?
1 in 6.3
people score this high or higher
84.1%
score at or below 115
Percentile Rank⧉
84.1th
84.13% score at or below 115
Z-Score⧉
1.00
Standard deviations from mean (SD=15)
Common Range Label⧉
Above Average Range
A descriptive band for the selected score scale, not a diagnosis or new test result
Rarity Estimate⧉
1 in 6.3
Approximate share who score this high or higher under the selected normal-curve model
One-SD Span⧉
100 — 130
A one-standard-deviation span around the reported score, not a test-specific confidence interval
Scale Used⧉
SD = 15
Standard IQ uses SD=15
| IQ Range | Common Range Label | Percentile | Rarity |
|---|---|---|---|
| 145+ | Exceptionally High Range | >99.9% | 1 in 1,000+ |
| 130-144 | Very High Range | 98-99.9% | 1 in 44 |
| 120-129 | High Range | 91-98% | 1 in 10 |
| 110-119 | Above Average Range | 75-91% | 1 in 4 |
| 90-109 | Average Range | 25-75% | 1 in 2 |
| 80-89 | Below Average Range | 9-25% | 1 in 4 |
| 70-79 | Low Range | 2-9% | 1 in 10 |
| <70 | Very Low Range | <2% | 1 in 44+ |
| IQ Score | WAIS Percentile | Cattell Percentile |
|---|---|---|
| 70 | 2.3% | 10.6% |
| 85 | 15.9% | 26.6% |
| 100 | 50.0% | 50.0% |
| 115 | 84.1% | 73.4% |
| 130 | 97.7% | 89.4% |
| 145 | 99.9% | 97.0% |
Planning notes, formulas, and examples
About the IQ Score Percentile Converter
The IQ Score Percentile Converter takes an already reported standardized IQ-style score and converts it to a z-score, percentile rank, and normal-curve rarity estimate using the selected scale mean and standard deviation.
This page does not measure intelligence, administer a test, or generate an official IQ result. It is a math converter for already-reported standardized scores.
The main value of the page is translating a reported score into percentile language that is easier to explain than raw standard-score math.
When This Page Helps
Percentiles are often easier to understand than the score alone. This converter helps restate a reported standardized score in normal-distribution terms without redoing the calculation by hand.
It is most useful for explanation and documentation, not for assessment.
How to Use the Inputs
- Select the score scale that matches the reported test.
- Enter the reported score from the original assessment.
- Review the percentile and z-score.
- Treat the descriptive band as a common label, not a diagnosis.
- Use the original test report for age-specific interpretation, confidence intervals, and clinical meaning.
Formula used
Z-score = (Score - Mean) / SD
Percentile = normal CDF(z) × 100
This page assumes a normal-distribution model for the selected standardized score scale.Example Calculation
Result: 84.1st percentile
On a scale with mean 100 and SD 15, a score of 115 is one standard deviation above the mean, which corresponds to about the 84th percentile. That is a mathematical restatement of the reported score, not a new assessment result.
Tips & Best Practices
- Use the same scale that the original report used.
- Treat the percentile as a restatement of the score, not as a separate test result.
- Use the original report for confidence intervals and interpretation limits.
- Do not use the page to label someone clinically based on the band alone.
- Rarity estimates are mathematical approximations.
- A standardized-score converter is only as good as the score you enter.
What This Page Does
It converts a reported standardized score into a percentile and z-score using the selected normal-distribution model.
What It Does Not Do
It does not administer a cognitive assessment, generate an official IQ, or replace a psychologist's report.
Best Use
Use it when you already have a reported score and want a quick percentile translation for explanation or documentation.
Sources & Methodology
Last updated:
Methodology
This page converts an already reported IQ-style standard score into z-score, percentile, and normal-curve rarity terms using the selected scale mean and standard deviation. It is a score converter only; it does not administer a test, generate a new IQ result, or reproduce publisher-specific confidence intervals or clinical interpretation.
The page assumes the reported score already came from an age-normed standardized assessment. That is why age is not a separate input here. The most defensible use is explaining a reported score in percentile language rather than treating the converter as an assessment tool.
Sources
- WAIS Scoring Assistant (Pearson Assessments) — Reference context for the WAIS family as an age-normed standardized IQ assessment framework.
- Stanford-Binet Intelligence Scales, Fifth Edition (Riverside Insights) — Reference context for the Stanford-Binet 5 score scale and reporting framework.
Frequently Asked Questions
It means the proportion of the modeled reference group that would score at or below the reported score under the selected distribution.
No. It only converts a score that has already been reported elsewhere.
Different tests use different standard deviations and norms, so the same raw score number can represent different percentiles depending on the scale.
Because a reported IQ-style score is usually already age-normed by the original test. Age-specific interpretation should come from the original report, not from this converter.
They are common descriptive ranges used in practice, but they are not universal diagnostic categories and should not replace the original test report.
No. It is a normal-distribution estimate derived from the selected scale model, not a publisher-issued rarity statement.
No. Formal interpretation should come from the original assessment report and the professional who administered the test.
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