Your child comes home from a mock exam having scored 42 out of 50. Is that good? On its own, that raw mark tells you almost nothing. The 11-plus is not reported as raw marks or percentages; it is reported as a standardised score (often shortened to SAS, for Standard Age Score). Understanding what a score of 121 actually means, and why two children who got the exact same raw mark can end up with different standardised scores, is one of the most useful things a parent can learn during the whole process. This plain-English guide explains how the 11-plus is really scored, how age standardisation quietly helps summer-born children, and how to read your child's mock results with confidence.
What a standardised score actually is
A standardised score converts a raw mark into a number on a fixed, comparable scale. Almost every UK 11-plus system (GL Assessment regions, the Kent Test, Medway, Buckinghamshire, CSSE in Essex) uses the same underlying statistical scale, built around two anchor points:
- The average score is set to 100. A child who performs exactly in line with the typical child of their age gets 100.
- The standard deviation is 15. This measures spread. Roughly two-thirds of children score between 85 and 115 (within one standard deviation), and about 95% fall between 70 and 130.
Because the scale is capped at both ends, standardised scores in the 11-plus typically run from about 69 or 70 up to 141. A score of 141 does not mean "141%"; it means the child is at the very top of the measurable range. This is why you cannot convert a standardised score back into "how many questions did they get right" without the specific conversion table for that paper.
Reading the numbers
| Standardised score | Roughly where the child sits |
|---|---|
| 100 | Exactly average for their age |
| 111 | Top ~25% of children |
| 115 | Top ~16% |
| 121 | Top ~10% (a common grammar qualifying score) |
| 130 | Top ~2% |
| 141 | Top of the scale |
So a standardised score of 121, the qualifying mark in Buckinghamshire and several other GL regions, places a child in roughly the top tenth of their age group. That is a far more meaningful statement than "42 out of 50".
Why raw marks are converted at all
Standardisation solves three problems in one step. First, it lets you compare performance across papers of different lengths and difficulty: 40/50 on a hard Verbal Reasoning paper and 45/60 on an easier Maths paper become directly comparable once standardised. Second, it lets scores from different subjects be added together fairly (an aggregate). Third, and most importantly for families, it adjusts for a child's age.
Age standardisation: the summer-born adjustment
This is the part that surprises most parents. Children sitting the 11-plus in September of Year 6 can be almost a full year apart in age. A child born in September is nearly 12; a child born the following August is barely 11. That extra eleven months of brain development, reading exposure and schooling is a genuine advantage on the day.
Age standardisation removes that unfair advantage. The system compares each child only against others born in the same month, then places everyone on the common 100/15 scale. In practice this means a younger (summer-born) child receives an uplift: the same raw mark earns them a slightly higher standardised score than an older autumn-born child would get.
Worked example: same raw mark, two birthdays
| Amara (born September) | Ben (born August) | |
|---|---|---|
| Age on test day | 11 years 11 months | 11 years 0 months |
| Raw mark | 42 / 50 | 42 / 50 |
| Age adjustment | None (oldest group) | Uplift for youngest group |
| Standardised score (illustrative) | 117 | 121 |
Both children answered the same number of questions correctly, but Ben, the summer-born child, receives a higher standardised score because more was achieved in less developmental time. The exact size of the uplift varies by paper and is set by the test provider's data, so the figures above are illustrative, not a fixed formula. The principle, however, is real and applies across GL, CSSE and the Kent and Medway tests.
Aggregates, weighting and qualifying scores
Many regions do not use a single standardised score; they add several together into an aggregate, sometimes with weighting. The Kent Test, for example, standardises English, Maths and Reasoning (Verbal plus Non-Verbal), then applies a weighting so no single subject dominates.
Worked Kent-style example
- English standardised: 118
- Maths standardised: 120
- Reasoning standardised: 116
To qualify, a child typically needs to reach an aggregate threshold (in recent years around 332) and score no lower than a set minimum (around 106) in any single subject. A child could hit the aggregate but be pulled up short by one weak paper, which is why balanced preparation across all four skills matters more than being brilliant at one. Our 11-plus revision plan and guide to the four subjects both explain how to spread practice evenly.
Qualifying score is not the same as a place
A crucial distinction: passing (reaching the qualifying standardised score) means your child is eligible for a grammar place. It does not guarantee one. Super-selective schools then rank all qualifying children by score and offer places from the top down, often with a cut-off well above the pass mark. Catchment, distance and admission criteria decide the rest. Reaching 121 in Bucks qualifies you; getting into an oversubscribed super-selective may need considerably more.
How to use standardised scores during practice
Mock scores are most useful as a trend, not a verdict. A single low mock can reflect a bad morning; three mocks drifting upward show real progress. Focus on which question types drag the score down, then drill those specifically. Quest Arena's free practice worksheets and timed full-length mocks report performance by question type so you can see exactly where marks are lost, and everything is free with no account needed. For provider-specific formats, see our GL papers hub and CSSE papers hub, and check your region's timeline on the key dates page.
A quick glossary
- Standardised score (SAS) - a raw mark converted to a common age-adjusted scale (average 100, SD 15).
- Age standardisation - adjusting scores so younger children are compared fairly against older ones.
- Aggregate - two or more standardised scores added together.
- Qualifying score - the mark needed to be eligible for a grammar place.
- Super-selective - a school that ranks and admits purely by score above the pass mark.
Frequently asked questions
What does a standardised score of 121 mean?
It means your child performed in roughly the top 10% of children their age. On the standard 100-average, 15-standard-deviation scale, 121 is about 1.4 standard deviations above average and is the qualifying mark in several GL regions such as Buckinghamshire.
Do summer-born children really get extra marks?
Not extra raw marks, but a higher standardised score for the same raw mark. Age standardisation compares each child only against others born in the same month, so a younger child's result is uplifted to account for their shorter time to develop and learn.
Is a standardised score the same as a percentage?
No. A percentage tells you how many questions were answered correctly on one paper; a standardised score places performance on a fixed, age-adjusted scale so results can be compared across papers, subjects and children of different ages.