What Is a Good IQ Score? IQ Ranges, Percentiles and What They Really Mean

Few numbers spark as much curiosity as an IQ score. You finish a test, see “118” and immediately wonder: is that good? The honest answer depends on how the score was built. Once you understand that, reading any IQ result becomes simple.

How IQ scores are calculated

Modern IQ tests don’t divide “mental age” by real age any more — that formula from the early 1900s broke down for adults. Instead they use a deviation IQ: your performance is compared with a large reference group of people your age, and the result is placed on a scale where:

• the average is 100,
• one standard deviation is 15 points,
• scores follow a bell curve (a normal distribution).

That bell curve is what gives IQ scores their meaning. Around 68% of people score within one standard deviation of the average (85–115), about 95% fall within two (70–130) and roughly 99.7% within three (55–145).

IQ score chart: ranges and what they mean

Different test publishers use slightly different labels, but the bands below are the ones you will see most often.

IQ to percentile: how many people you outscore

A percentile tells you the share of people who score below you. It is often the easiest way to understand an IQ result.

Notice how quickly rarity grows at the top. Moving from 100 to 115 lifts you above a third of the population; moving from 130 to 145 lifts you above only about 2% more — but makes the score about 17 times rarer.

So, what counts as a “good” IQ score?

Because 100 is the middle by definition, any score above 100 is above average, and most people would call a score of 110 or more a good result. A few useful reference points:

• 110–119: comfortably above average. You outperform roughly three out of four people.
• 120–129: strong reasoning ability — higher than about 90% of people.
• 130+: the top 2–3%, the range associated with high-IQ societies such as Mensa.

A score just below 100 is not “bad” either. Half of all people score below average — that is simply how the scale is designed.

What is the average IQ?

The average IQ is 100 at every age, because each age group is compared only with itself. A 12-year-old who scores 100 performs like a typical 12-year-old; a 60-year-old who scores 100 performs like a typical 60-year-old.

You may have seen rankings of “average IQ by country”. Treat them with caution: they combine very different tests, samples and years, and are strongly influenced by schooling, health and test familiarity. They say little about any individual.

Averages also drift over time. During the 20th century, raw scores on many tests rose by around three points per decade — the so-called Flynn effect — which is why tests are periodically re-normed so that 100 stays the middle.

Why your IQ score can vary by a few points

No test measures anything perfectly. Even professionally administered IQ tests report scores with a confidence interval of roughly ±5 points. Things that commonly move a result:

1. Measurement error. A different set of questions samples your ability slightly differently.
2. Practice effects. Retaking the same kind of test usually raises scores a little because the formats feel familiar.
3. Your state on the day. Sleep, stress, time pressure and distractions all matter.
4. The type of test. A test heavy on vocabulary measures something different from one built on visual patterns.

That is why a single score is best read as a range: 118 really means “somewhere around the high-average-to-superior boundary”.

How online IQ tests compare with clinical tests

Clinical tests such as the Wechsler scales are administered one-to-one by a trained psychologist, take over an hour and are normed on carefully selected national samples. They are used for diagnosis and educational decisions.

A well-designed online test is a different tool: faster, cheaper and useful for self-discovery and practice, but not a diagnosis. On IQtonics you answer 40 questions across five areas — patterns, spatial reasoning, numbers, logic and memory — in about 20 minutes. Harder questions carry more points, and your weighted score is placed on the same mean-100, standard-deviation-15 scale described above, so the percentile you see is read exactly as in the chart. If you want to know what those questions look like, read our guide to the five types of IQ test questions.

What an IQ score doesn’t tell you

IQ tests measure reasoning, pattern recognition, working memory and processing speed — abilities that predict success at learning complex material. They do not measure creativity, motivation, emotional skills, expertise or character, all of which shape real-world outcomes at least as much. A good IQ score is a strength, not a destiny.