Ask ten people what a "good" IQ score is and you'll get ten different answers. The honest one is a percentile. IQ is a scaled score, built so that the average of a population is 100 and scores spread along a bell curve with a standard deviation of 15 points. Once you have those two numbers, every band below is arithmetic.
IQ score ranges: score, percentile and label
The percentile is the share of people who score at or below that number on the same scale. It isn't a judgement — it's a position on the curve.
| IQ score | Percentile | Band label |
|---|---|---|
| 70 | 2nd | Borderline |
| 85 | 16th | Low average |
| 90 | 25th | Low average |
| 100 | 50th | Average |
| 110 | 75th | Average to high average |
| 115 | 84th | Above average |
| 120 | 91st | Above average |
| 121 | 92nd | Above average |
| 125 | 95th | Above average |
| 130 | 98th | Gifted range |
| 135 | 99th | Gifted range |
| 145 | 99.9th | Gifted range |
The IQ test bell curve and standard deviation
Standard deviation is the width of the curve. On the IQ scale it is 15 points, which is where the familiar rules of thumb come from: - About 68% of people score within one standard deviation of the mean — between 85 and 115 - About 95% score within two — between 70 and 130 - Fewer than 3% score above 130 or below 70
These aren't arbitrary bands — they fall out of the bell curve. The specific test labels differ between clinical instruments (WAIS, Stanford-Binet, Raven's) but the statistical structure is identical: same mean, same spread, same percentiles.
Is 121 a good IQ? And 120? And 130?
These three come up more than any others, so here they are side by side: - 120 is about the 91st percentile — ahead of roughly nine people in ten. - 121 is the 92nd percentile. That single point moves you past about 1% of the population, which is well inside the measurement noise of any one sitting. Treat 120 and 121 as the same result. - 130 is the 98th percentile (97.7%, precisely) — about 1 person in 44, and the threshold most "gifted" programmes and Mensa use.
All three are good scores on any reading of the word. The more useful question is what they are good for, which is further down.
Is there a perfect IQ score?
No — and the question hides an assumption worth undoing. IQ isn't a percentage or a mark out of 100. It's a position on a curve that has no top, defined by where you sit relative to everyone else rather than by how many items you cleared. There is no "all correct" number to reach.
What a test can report is capped by its hardest questions. A test with no items above a given difficulty simply can't separate the people at the top of it, so its highest reportable score is a fact about the test, not about the person taking it.
The 98th percentile and above
Past 130 the curve thins out fast: - 130 — 98th percentile, about 1 in 44 - 135 — 99th percentile, about 1 in 100 - 140 — about 1 in 260 - 145 — 99.9th percentile, about 1 in 750
Every five points roughly halves the number of people above you. That's also why differences at the top are much harder to measure than differences in the middle: there are fewer people, and fewer suitably hard questions, to calibrate against.
What the average IQ is for a 12-year-old — and every other age
It's 100. Modern IQ is a deviation score, which means it compares you with your own age group rather than with adults in general. The average for 12-year-olds is 100 by construction, exactly as it is for 30-year-olds. A 12-year-old scoring 115 is one standard deviation above other 12-year-olds — not above the adult population. Age-norming is the whole point of the deviation approach, and it's why "IQ for my age" and "IQ" are the same number.
Band by band, in words
**70–84 (Borderline)**: About 14% of people. Many live fully independent lives; the band includes people with learning difficulties who need support, and people without any diagnosis who just process information more slowly.
**85–99 (Low Average)**: About 34% of people. Completely within normal function. Often outperforms higher-IQ peers in real-world work due to conscientiousness and motivation.
**100–114 (Average to High Average)**: The biggest chunk of the population. 100 is the exact midpoint. Scoring 110 means you're ahead of about 75% of people on this specific type of reasoning test.
**115–129 (Above Average)**: About 14% of people. Correlates with success in demanding academic fields, professional roles and research positions. Most doctors, engineers and senior managers score here.
**130+ (Gifted)**: About 2% of people. Scores above 145 are roughly 1 in 750. These are clinical-level scores, not something to claim from a 20-question online test.
Why online IQ tests measure below 130
Online IQ tests, including ours, typically measure well below 130 with any reliability. Short tests have too few high-difficulty items to distinguish between a 130 and a 150. A clinical test has 60-100+ items specifically calibrated to separate scores at the upper end. If you score "exceptional" on an online test, treat it as "above average at minimum" — not as a precise number.
What "good" depends on
- **For school and work**: Above 100 is genuinely helpful. Above 115 opens doors in demanding cognitive fields.
- **For life satisfaction**: Almost no correlation above 100. People at 100 report similar life satisfaction to people at 140.
- **For specific careers**: Research suggests a soft threshold effect — around 120, IQ stops predicting performance in many creative fields, because other factors (drive, conscientiousness, social skills) take over.
Why IQ isn't everything
Psychometric research consistently finds that: - Conscientiousness predicts job performance about as strongly as IQ - Emotional intelligence predicts leadership success more than IQ - Grit and deliberate practice compound over years to beat raw talent
IQ opens some doors. It doesn't hand you anything behind them.
What your score is telling you
Focus less on the exact number and more on: - Which question areas you did well in (pattern recognition vs verbal vs numerical) - Where you slipped (that's practice territory) - Whether it matches your sense of your own strengths
If you haven't taken our 40-item screener yet, it'll give you a band and a breakdown by skill area. It won't tell you your IQ to three significant figures — no online test can — but it will point you at what to practise.
