Intelligence Test
Scores
Complete guide to understanding your intelligence test scores: what they mean, how they're interpreted, percentile rankings, benchmark data and score classifications. Interactive calculator showing IQ scores, percentiles and classifications.
Use Score Calculator →What is an IQ score?
An IQ (Intelligence Quotient) score is a standardised measure of cognitive ability relative to the population. The average score is always set at 100, with a standard deviation of 15 points. This means roughly 68% of people score between 85 and 115. Your score reflects how your reasoning ability compares to others your age and background. An IQ score is a snapshot of your current cognitive performance, not a measure of your worth, potential or character.
How IQ scores are calculated
IQ = (Mental Age ÷ Chronological Age) × 100. This classical formula is now replaced by standardised scoring: your raw test answers are converted to a scale where 100 is average and each 15 points represents one standard deviation. If your score is 115, you're one standard deviation above average. If it's 85, you're one standard deviation below average. The standard deviation of 15 points is industry standard across professional IQ tests (WAIS, Stanford-Binet, etc.).
What IQ scores measure
IQ tests measure general cognitive ability — particularly reasoning, pattern recognition, problem-solving and processing speed. They predict academic success, professional performance and learning capacity better than any other single metric. However, IQ scores do NOT measure: creativity, emotional intelligence, wisdom, practical ability, motivation, character or worth as a person. A high IQ indicates strong reasoning ability; it does not guarantee success, happiness or life achievement.
IQ scores follow a normal distribution. The classifications below represent standard interpretations used across psychology and education.
| IQ Score Range | Classification | Percentile | Approximate Population % |
|---|---|---|---|
| 130+ | Very Superior | 98th+ | 2.2% |
| 120–129 | Superior | 91st–98th | 6.7% |
| 110–119 | High Average | 75th–90th | 16.1% |
| 100–109 | Average | 25th–74th | 50% |
| 90–99 | Low Average | 9th–24th | 16.1% |
| 80–89 | Below Average | 2nd–8th | 6.7% |
| Below 80 | Significantly Below Average | Below 2nd | 2.2% |
Enter your IQ score to see your classification, percentile rank and interpretation.
Your score on any given day is affected by many factors beyond your actual cognitive ability. Understanding these helps you interpret your results realistically.
📅 Testing Environment
Noise, distractions, temperature and comfort all affect performance. Professional testing controls these factors; online testing may not.
😴 Fatigue & Sleep
Sleep deprivation can reduce IQ test performance by 5–15 points. Taking a test when well-rested yields more accurate results.
😰 Stress & Anxiety
Test anxiety temporarily reduces performance. Professional environments and individual attention reduce this effect.
🎯 Motivation
Effort and motivation significantly affect scores. Taking a test casually yields lower scores than focused, motivated attempts.
💊 Health & Illness
Being unwell, hungover or on medication can reduce scores. Retest when healthy for accurate measurement.
📖 Practice Effect
Taking similar tests repeatedly can improve scores 5–10 points due to familiarity. First attempts are typically most accurate.