IQ Percentile Calculator – Check Your IQ Percentage | DietDekho
🧠 Free Cognitive Tool

IQ Percentile Calculator
Check Your IQ Percentage

Enter your score and test standard deviation to instantly calculate your IQ Percentile. Understand exactly where your intelligence stands on the statistical bell curve.

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Z-ScoreBased Method
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Calculate Your Percentile

Find out how your score compares to the population

Select the standard deviation used by your IQ test.

Enter the total score you received on the test.

Points
Please enter a valid IQ score.
Understanding the Math

What Is An IQ Percentile?

Your IQ Percentile is a statistical representation of how your intelligence test score compares to the general population. Because IQ scores are mapped on a normal distribution curve (a bell curve), knowing your raw score doesn't tell the whole story until you understand its percentile.

For instance, if your score places you in the 98th percentile, it means you scored higher than 98% of the people who took the test, placing you in the top 2% of the population.

Score Interpretation
IQ Categories Chart

How to Interpret Your IQ Score

IQ Range (SD 15) Classification Estimated Percentile Population Rarity
130 and above Very Superior / Gifted 98th to 99th+ Top 2%
120 - 129 Superior 91st to 97th Top 9%
110 - 119 High Average 75th to 90th Top 25%
90 - 109 Average 25th to 74th Middle 50%
80 - 89 Low Average 9th to 24th Bottom 25%
Understanding The Factors
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Standard Deviation (SD)

Different tests use different scales. Wechsler scales use an SD of 15, meaning a score of 115 is one standard deviation above the mean. A Cattell test uses an SD of 24, making a 124 equivalent to a Wechsler 115.

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The Bell Curve

Intelligence follows a normal distribution. The vast majority of people (about 68%) score within one standard deviation of the average (between 85 and 115 on a standard WAIS test).

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The Z-Score

To calculate your percentile, your raw score is converted to a Z-score, which measures exactly how many standard deviations away from the average of 100 your score lies.

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Nutrition & Cognition

While IQ is largely stable over a lifetime, cognitive function (focus, memory, clarity) heavily fluctuates based on lifestyle factors, especially proper nutrition and diet.

Enhance Cognitive Health
Actionable Advice

How to Fuel Your Brain for Peak Performance

  • 1
    Prioritise Omega-3 Fatty Acids — Your brain is nearly 60% fat. Consuming foods rich in Omega-3s, like walnuts, chia seeds, flaxseeds, and fatty fish, helps build brain and nerve cells, essential for learning and memory.
  • 2
    Stay Hydrated — Even mild dehydration can impair cognitive functions like attention, memory, and motor coordination. Aim for adequate water intake throughout the day to keep your brain functioning efficiently.
  • 3
    Eat Antioxidant-Rich Foods — Berries, dark chocolate, and leafy greens contain antioxidants that reduce cellular stress and inflammation, which are linked to brain aging and neurodegenerative diseases.
  • 4
    Don't Skip Complex Carbs — The brain relies heavily on glucose for fuel. Complex carbohydrates like oats, quinoa, and brown rice provide a steady, slow-releasing energy source to prevent brain fog.
  • 5
    Prioritise Sleep & Recovery — Your brain consolidates memories and clears out neurotoxins while you sleep. Poor sleep directly impairs problem-solving skills and reasoning abilities, temporarily mimicking a lower cognitive score.
FAQs

Common Questions About IQ & Percentiles

Why does the standard deviation matter? +
Different IQ tests scale their scores differently. A score of 130 on a test with a standard deviation of 15 (like WAIS) puts you in the 98th percentile. However, a score of 130 on a test with a standard deviation of 24 (like Cattell) only puts you in the 89th percentile. Knowing the SD is crucial for accurate calculation.
Can my IQ percentile change over time? +
Your IQ score is designed to be relatively stable throughout adulthood. While your raw cognitive processing speed might naturally slow as you age, the percentile compares you to your peers of the same age group, so the percentile ranking usually remains stable.
What is considered a "good" IQ percentile? +
An average IQ score is exactly 100, which sits at the 50th percentile. Anything above the 50th percentile is above average. Scores falling in the 75th percentile (IQ 110) are considered "High Average," while scores in the 98th percentile (IQ 130) are considered "Gifted."
Does diet actually impact intelligence? +
Diet does not permanently alter your baseline intelligence quotient (IQ). However, severe nutritional deficiencies can prevent the brain from functioning optimally. A balanced diet ensures your brain has the energy, neurotransmitter precursors, and structural fats it needs to perform at its maximum natural capacity.
How accurate is this percentile calculator? +
This calculator uses exact statistical formulas (the Normal Cumulative Distribution Function) to map Z-scores to percentiles based on an ideal bell curve. It provides a mathematically accurate percentile for the standard deviation and score you enter.
Disclaimer: This IQ Percentage Calculator is provided for educational and informational purposes only. It is not a clinical diagnostic tool. For professional cognitive assessment or medical advice, please consult a licensed psychologist or medical professional.