IQ Score Range — Every Band on the Scale, Explained

On the mean-100, SD-15 scale, the natural IQ score range boundaries fall where the standard deviations fall. Within one deviation of the mean (85–115) sits about 68 percent of the reference distribution; a second deviation out (70–130) brings the total to about 95 percent; the remaining slivers sit beyond. The table in the tool turns that geometry into six bands. Every IQ score range boundary falls where the deviations fall.

Read the shares as model values, not measurements of any real classroom or country. The percentages come from the normal distribution with mean 100 and SD 15 — the common convention — rounded to two decimals: the 85–115 band holds 68.27 percent, 70–130 holds 95.45 percent, and each half of the central band holds 34.13 percent. A different publisher using SD 16 or different cutoffs shifts the numbers slightly, which is why the tool shows the model it uses. Model values, honestly labeled, are what an IQ score range table owes you.

What the bands do not come with is judgement. Each label in this tool is a direction and distance from the mean — 'above the reference mean', 'very high on the reference scale' — rather than the old clinical-sounding tier names. The next section explains why that vocabulary choice is deliberate. Each IQ score range below is a location, and every label keeps to that contract. Position language is the contract behind each IQ score range here.

• 1130 and above: very high on the reference scale — about the top 2%
• 2115–129: above the reference mean — roughly the 84th–98th percentile
• 3100–114: just above the reference mean — upper half of the central band
• 485–99: just below the reference mean — lower half of the central band
• 570–84: below the reference mean — roughly the 2nd–16th percentile
• 6Below 70: well below the reference scale — under about the 2nd percentile

Older test manuals layered evaluative and clinical-sounding names onto the bands. Those names carried two problems. First, they smuggled diagnosis into a statistical description: an IQ score range cannot detect, diagnose, or rule out any condition — that requires clinical assessment of the whole person. Second, tier names invite ranking people rather than locating scores, which the number cannot support either. The vocabulary lesson matters as much as the boundaries of any IQ score range. Vocabulary discipline matters as much as any IQ score range boundary.

So this page's IQ score range finder sticks to position language: distance and direction from the mean. If you need the historical labels for a report you are reading, many publishers' versions map onto the same breakpoints — roughly: below 70 extremely low, 70–84 borderline to low average, 85–99 average-lower, 100–114 average-upper, 115–129 high average to superior, 130+ very superior — but the mapping varies by manual and by decade, and no modern professional reads a band name as a verdict. Different manuals, same geometry — that is the IQ score range reality.

One more honesty note: boundaries are conventions, not cliffs. A 114 and a 116 sit two points apart — closer to each other than either is to their band's edge — yet they land in different bands. Use the IQ score ranges as bins for orientation, not as thresholds that change what a score means. Bins, not cliffs — the honest way to read any IQ score range. Bins, not cliffs: the only honest way to read an IQ score range.

A band usefully summarizes position: knowing a score sits in the 115–129 range tells you it is one to two deviations above the reference mean — roughly between the 84th and 98th percentile of the standardization sample. For orientation, for interpreting a report you already hold, that summary is exactly the right amount of information. For orientation, an IQ score range summary is exactly the right resolution. For orientation, an IQ score range summary is the right resolution.

It cannot do the heavier lifting people sometimes ask of it. An IQ score range does not diagnose anything; does not measure effort, character, or knowledge; does not fix a person's ceiling — scores move a few points across retesting and lifespan; and does not transfer across tests with different norms. And crucially it says nothing about the untimed, unnormed practice quizzes on this site: their results are accuracy percentages, which are not on this scale at all. The IQ score range carries none of that heavier cargo.

If you arrived without a score and want the other direction — practicing the skills these tests sample — the homepage's mixed quiz and the puzzle page are the right doors. If you want the math behind the bands, the test-scale page derives z-scores, and the bell-curve page shows the areas the percentages come from. Both directions sit one click from this IQ score range finder. Both directions sit one click from this IQ score range finder.

Two ranges attract most questions. The 130+ band is often quoted in gifted-program criteria — a program may set an entry cutoff at approximately the 98th percentile, which on the SD-15 model lands at about 130. But programs vary widely and combine multiple criteria, so a band alone never decides admission. The 70–84 and below-70 bands appear in discussions of support needs — yet by themselves they indicate only position below the mean; any statement about support requires full clinical assessment, history, and adaptive-functioning measures, not a single number. A cutoff near an IQ score range edge is where error bars matter most.

Both examples repeat the same lesson from different ends of the scale: an IQ score range is a statistical location with real, bounded uses — orientation, research grouping, one input among many in professional assessment — and a poor basis for decisions it was never built to inform. The tool above keeps that spirit: enter a score, get its position, read the band, and carry away the number rather than a label. Every example above is, at heart, a lesson about reading an IQ score range responsibly. Every example is a lesson in reading an IQ score range responsibly.