CAT4 Standardised Scores and SAS Explained (2026): What a 120 Actually Means

1. Home
2. ›
3. Blog
4. ›
5. CAT4 Standardised Scores and SAS Explained

A CAT4 score report lands with four numbers, a "Mean SAS," and very little explanation of what any of it means. If your child's report shows a Standardised Age Score of 120, or 96, or 141, this guide explains exactly what that number represents: how GL Assessment calculates it, what it means relative to other pupils the same age, how it converts to a percentile, and where the 120-130 range that some schools use for "highly able" or "gifted" identification actually comes from. This page focuses specifically on the scoring mechanics. If you want a broader introduction to what CAT4 is, how it is administered, and why schools use it, see our companion guide, CAT4 Test Explained for Parents.

What Is a CAT4 Standardised Age Score (SAS)?

The Cognitive Abilities Test, Fourth Edition (CAT4) is published by GL Assessment and comprises four batteries — Verbal Reasoning, Non-Verbal Reasoning, Quantitative Reasoning and Spatial Ability — each producing its own Standardised Age Score, plus an overall Mean SAS across all four. GL Assessment states that CAT4 is standardised on a sample of around 25,000 pupils and re-verified annually against data from roughly a quarter of a million pupils nationally, which is what allows the scale to stay statistically stable year on year.

The SAS scale itself is built with a mean of 100 and a standard deviation of 15, and in practice scores across a full cohort span roughly 69 to 141. A SAS of 100 always means "exactly typical for pupils of this age" — not typical for the year group as a whole, but typical for pupils of that pupil's specific age in years and months. That distinction is the single most important thing to understand about how CAT4 differs from a simple raw mark, and it is covered in detail in the next section.

How Does CAT4 Turn a Raw Score Into a Standardised Age Score?

Every pupil sitting CAT4 first generates a raw score for each battery — simply the number of items answered correctly out of the total available. On its own, a raw score tells you almost nothing useful, because pupils in the same class or year group can be up to twelve months apart in age, and cognitive reasoning ability develops quickly at primary and early secondary age. A raw score that is impressive for an 8-year-old and 3 months old pupil might be unremarkable for a pupil who is 8 years and 11 months old, even though both sat an identical set of questions.

GL Assessment resolves this by converting each raw score into a Standardised Age Score using the pupil's exact chronological age in years and months on the day of testing — not their school year, and not their year-group cohort as a single block. The raw score is compared only against the standardisation data for pupils of that same precise age band. This is why two pupils in the same class, sitting the same test paper on the same day and getting the same number of raw marks correct, can receive two different SAS scores if one of them is several months older than the other. The age-adjustment exists specifically to stop summer-born pupils being systematically disadvantaged against their autumn-born classmates, and it is one of the main reasons schools trust CAT4 SAS scores over an unadjusted raw mark or a simple year-group rank.

CAT4 SAS Score Bands: What Each Range Means

GL Assessment's SAS scale can be grouped into broad bands that many schools use as shorthand when discussing a pupil's results. These labels are descriptive, not official pass/fail categories — CAT4 has no pass mark.

What Does a CAT4 Score of 120 Actually Mean?

Take the number in this page's title. A SAS of 120 is 20 points above the mean of 100. Because the scale's standard deviation is 15, that gap is 20 ÷ 15 = 1.33 standard deviations above average — what statisticians call a z-score of 1.33. If CAT4 scores follow a normal distribution across the standardisation sample (which is how GL Assessment designs the scale), a z-score of 1.33 corresponds to roughly the 91st percentile. In plain terms: a pupil scoring 120 performed better on that battery than approximately 9 out of every 10 same-age pupils in the standardisation sample.

That places a SAS of 120 firmly in the "Above Average" band shown in the table above. It is a genuinely strong result — well above typical for the pupil's age — but it sits below the 126-130+ range that a number of schools additionally use as a threshold for gifted or scholarship-track review (see below). A single 120 on one battery, say Non-Verbal Reasoning, alongside three scores closer to 100-110 on the other batteries, usually indicates a pupil with a particular strength in that reasoning style rather than uniformly exceptional ability across the board — and that is exactly the kind of profile CAT4 is designed to surface.

The table below works through several specific SAS values using the same method, so you can translate any number on your child's report into an approximate percentile without needing to redo the calculation yourself.

Percentiles above are approximate, calculated from the standard normal distribution that the SAS scale is modelled on. GL Assessment also reports an official National Percentile Rank (NPR) alongside each SAS on the pupil's actual score report, which is derived from the real standardisation sample rather than a theoretical calculation — treat the NPR on your child's report as the precise figure and the table above as a way to sanity-check any SAS value at a glance.

What About Below-Average Scores? What Does 85 or 90 Mean?

A SAS of 85 sits one full standard deviation below the mean, which maps to roughly the 16th percentile — the pupil scored lower than about 84% of same-age pupils on that specific battery, or equivalently, higher than about 16%. A SAS of 90 is a smaller gap below average, closer to the 25th percentile. Both fall in the "Below Average" or lower end of "Average" bands, and both are common, unremarkable results that appear on a meaningful proportion of every cohort simply because CAT4 is standardised — by design, roughly a third of pupils nationally will score below 90 on any given battery.

The important context that gets lost in a single number is that CAT4 measures four distinct types of reasoning, and a below-average score on one battery next to average or above-average scores on the other three is one of the most common patterns schools see. A pupil who scores 90 on Spatial Ability but 108-114 on Verbal, Quantitative and Non-Verbal Reasoning does not have a general cognitive weakness — they have a reasoning profile that is simply less spatially oriented, which is entirely normal variation rather than a cause for concern. Schools using CAT4 well are trained to read the four-battery profile as a whole rather than reacting to any single below-average figure in isolation, and parents are well within their rights to ask a school for that fuller picture rather than a headline number.

Do Schools Use 126 or 130 as a Gifted or Scholarship Threshold?

This is one of the most-asked questions from parents, and the honest answer is: it depends entirely on the school, because GL Assessment does not publish a single official cut-off for "gifted" identification. What GL Assessment provides is the score; individual schools set their own policy for what they do with it. That said, some consistent patterns show up across schools that do use CAT4 for this purpose:

A number of schools treat a SAS of 120-129 as an indicator that a pupil should be flagged as "highly able" and considered for additional stretch or enrichment, particularly when combined with classroom attainment evidence. Scores of 130 and above are more commonly associated with a formal "gifted" or "gifted and talented" identification, again usually cross-checked against actual subject performance rather than used as a standalone trigger. Other schools set the bar for scholarship-track review lower, around 121-126, especially where the CAT4 Mean SAS (the average across all four batteries) is used rather than any single battery score in isolation.

What this means practically: if your child's Mean SAS is 126 and you are hoping this qualifies them for a specific school's academic scholarship, the only way to know for certain is to ask that school what threshold and process they actually use — some will look at the Mean SAS, others weight particular batteries more heavily depending on the subject area the scholarship targets, and some do not use CAT4 for scholarship decisions at all. Treat any number you read on a prep website (including the ranges above) as a general guide to how schools tend to use CAT4 data, not as a guarantee of how any one school will interpret your child's specific report.

How Is a CAT4 SAS Different From a Percentile Rank?

A SAS and a percentile describe the same result in two different formats, and it helps to be clear on why GL Assessment reports both. The SAS is a scaled score — mean 100, standard deviation 15 — that behaves like a ruler with equal-sized steps. That property makes it mathematically sound to compare a pupil's SAS across the four different CAT4 batteries, or to track how a pupil's SAS changes if they sit CAT4 again in a later year group, because a 10-point gap means the same thing wherever it falls on the scale.

A percentile, by contrast, tells you what share of the standardisation sample a pupil's performance beat — nothing more, nothing less. A percentile of 91 means the pupil outscored 91% of same-age peers in the sample; it does not tell you how large or small the underlying performance gap actually was. This matters because percentiles compress heavily at the extremes: the raw-score gap between the 98th and 99th percentile is far larger than the gap between the 50th and 51st, even though both represent a one-point move on the percentile scale. That is precisely why GL Assessment treats the SAS as the primary reported figure and includes the National Percentile Rank (NPR) as a secondary, more intuitive number alongside it — the SAS is the more statistically reliable figure for comparison and tracking, while the percentile is the easier one to explain to a parent in a five-minute conversation.

What Is a Stanine, and How Does It Relate to SAS?

Some CAT4 reports also show a stanine ("standard nine") score, which compresses the SAS scale into nine broad bands numbered 1 to 9, with a mean of 5. Stanines are a deliberately coarser measure than SAS or percentile — they exist to give a quick, low-precision snapshot without over-interpreting small numeric differences that are within normal measurement variation. Broadly, stanine 9 corresponds to the top few percent of the SAS distribution (SAS scores from the upper-120s upward), stanines 7-8 cover the upper-average to above-average range, stanines 4-6 cover the broad average band either side of a SAS of 100, and stanines 1-3 cover below-average to low results. Because a single stanine band can span more than a full standard deviation of SAS scores, two pupils in the same stanine can still have meaningfully different SAS values — the stanine is a useful "at a glance" indicator, but the SAS remains the more precise figure for any decision that actually matters, such as setting, streaming, or scholarship review.

Is a CAT4 SAS the Same as an 11+ Standardised Score?

No, although the underlying statistics — mean 100, standard deviation 15, age-adjustment — are calculated the same way, which is exactly why the two are so often confused. CAT4 is a reasoning-ability assessment used by many secondary and independent schools primarily for setting, streaming, and identifying pupils who might need additional challenge or additional support; it is not, on its own, an entrance exam, and most children who sit it are already enrolled at the school administering it. An 11+ standardised score, covered in detail in our 11+ standardised scores guide, is instead calculated directly from a pupil's raw marks on that region's actual verbal reasoning, non-verbal reasoning, maths, and English entrance papers, adjusted using the same age-standardisation principle.

Where the two do overlap is in independent school entrance assessment. A number of independent senior schools use CAT4, or the related GL Assessment Cognitive Abilities Pre-Test, as one component of their Year 6 or Year 7 entrance process, sometimes alongside or instead of the ISEB Common Pre-Test — see our guide to the ISEB Common Pre-Test for how that specific assessment compares. A family going through independent school admissions may therefore see a CAT4-style SAS on one school's report and an 11+ or Pre-Test standardised score on another's within the same admissions round, and it is worth checking with each school exactly which assessment they use and how they weight it before assuming the two numbers are directly comparable.

How Should Parents Read a Full CAT4 Score Report?

A complete CAT4 report shows four separate SAS figures — one each for Verbal Reasoning, Non-Verbal Reasoning, Quantitative Reasoning and Spatial Ability — plus a Mean SAS that averages all four. Reading the report well means resisting the urge to focus on the single highest or lowest number and instead looking at the shape of the whole profile.

A "flat" profile, where all four batteries land within about 10-15 points of each other, suggests a fairly even reasoning style across verbal, non-verbal, numerical and spatial thinking. A "spiky" profile, where one or two batteries sit well above or below the others, is just as common and is usually far more informative for a school or tutor than the Mean SAS alone, because it points to a specific reasoning strength or a specific area that would benefit from targeted support. For example, a pupil with Verbal Reasoning at 115, Quantitative Reasoning at 118, but Spatial Ability at 92 is not "average overall" in any meaningful sense — they have clear relative strengths in verbal and numerical reasoning and comparatively weaker spatial reasoning, and a school or tutor working from the Mean SAS alone (around 108-109 across those figures) would miss that pattern entirely.

It is also worth remembering that CAT4 measures reasoning style and developed ability at the point of testing — it is not a fixed IQ-style ceiling, and reasoning profiles genuinely do shift as pupils mature and as their exposure to different types of problem-solving changes. A below-average Spatial Ability score at age 9 is a snapshot, not a life sentence, and it is entirely normal for a re-test 12-18 months later to show meaningful movement, particularly if a pupil has had the chance to practise that specific style of reasoning in the interim.

For families preparing for the entrance assessments that sometimes sit alongside CAT4 in an admissions round, our 11+ tuition programmes are built around exactly this kind of profile analysis — identifying which reasoning areas need the most attention rather than applying a one-size-fits-all revision plan.

Frequently Asked Questions