IQ Score Ranges Explained: What Every Number on the Scale Means

One of the most common questions after taking an IQ test is: "Is my score good?" The answer depends entirely on where that score sits on the IQ distribution. This guide breaks down every range on the IQ scale with percentiles, classifications, and real-world context.

How the IQ Scale Works

IQ scores are designed so that 100 is always the average for any given age group. The scale has a standard deviation of 15 — meaning each 15-point step represents one standard deviation from the mean. This matters because:

• IQ 115 = 1 standard deviation above average = 84th percentile
• IQ 130 = 2 standard deviations above average = 98th percentile
• IQ 85 = 1 standard deviation below average = 16th percentile

The scale doesn't have a hard ceiling. Clinically, scores above 145 are rarely reliable due to ceiling effects in test instruments. Scores below 70 are considered diagnostically significant for intellectual disability assessment.

IQ Score Ranges and What They Mean

IQ 145+ — Exceptionally Gifted / Profoundly Superior

Percentile: 99.9th+. Fewer than 1 in 1,000 people score in this range. This is the territory associated with prodigies and exceptional academics. Note that most online tests cannot reliably differentiate above IQ 130–135 due to ceiling effects.

IQ 130–144 — Very Superior

Percentile: 98th–99.9th. This is the threshold for membership in high-IQ societies like Mensa (which requires the 98th percentile or above). About 2–3% of the population scores here. Associated with academic excellence and fast learning across complex domains.

IQ 120–129 — Superior

Percentile: 91st–97th. Roughly 9% of people score in the superior range. Strongly associated with success in demanding academic and professional fields. Most doctoral-level academics cluster here and above.

IQ 110–119 — High Average

Percentile: 75th–90th. About 16% of the population scores in the high average range. This group consistently outperforms the majority in academic settings and excels in professional environments that reward analytical thinking.

IQ 90–109 — Average

Percentile: 25th–74th. Approximately 50% of people score in the average range. This is the cognitive "normal" — fully capable of completing standard academic work and thriving in the vast majority of occupations.

IQ 80–89 — Low Average

Percentile: 9th–24th. About 16% score here. Individuals in this range generally complete compulsory education successfully but may find certain advanced academic programs more challenging.

IQ 70–79 — Borderline

Percentile: 2nd–8th. The borderline range. Individuals here are not classified as having an intellectual disability (which requires IQ below 70 plus significant adaptive functioning deficits), but may need additional support in academic settings.

IQ Below 70 — Below Average / Intellectual Disability Range

Percentile: Below 2nd. Clinical IQ scores below 70, combined with deficits in adaptive functioning, are one of the criteria for intellectual disability diagnosis. This determination requires a comprehensive clinical evaluation — not an online test.

What Is the Average IQ Score?

By definition, the population average IQ is exactly 100. But "average" varies by country and era. The Flynn Effect — a documented rise in IQ scores across generations — means that raw scores have risen about 3 points per decade globally since the 1930s. Tests are periodically re-normed to maintain the 100 average.

What Does a High IQ Predict?

Research consistently shows IQ is the single strongest predictor of:

• Academic achievement
• Job performance (especially in complex roles)
• Income (though the correlation is modest)
• Learning speed

But IQ is not destiny. Studies of highly successful people show that conscientiousness, emotional intelligence, and opportunity matter as much or more than raw cognitive ability.

What Is the Mensa IQ Requirement?

Mensa International — the world's oldest and largest high-IQ society — requires members to score in the top 2% of the population, which corresponds to an IQ of approximately 130 on the Wechsler scales or 132 on the Stanford-Binet. Members must use an approved IQ test administered by a psychologist.

Find Out Where You Score

The best way to understand your position on the IQ scale is to take a well-structured cognitive assessment. IQ Test Center's free online IQ test gives you an estimated composite score plus a breakdown across five cognitive domains — completely free with an account. See how scoring works →