Age standardisation is the mechanism that adjusts a child's raw 11+ score for their age within the school year, so that older and younger candidates are compared fairly.
Why it exists
Within a single school year, the oldest child can be eleven months older than the youngest. At age ten, eleven months is a meaningful chunk of cognitive and emotional development — without an age adjustment, summer-born children would be systematically disadvantaged.
Age standardisation gives a small uplift to younger children and a small offset to older children, calibrated to remove (rather than create) age advantage in the final scaled score.
How big is the adjustment
The size of the age adjustment varies by provider and by year, but as a rough guide a summer-born child (August birthday) typically receives a several-point uplift over a September-born child of identical raw performance. The exact figure is provider-specific and not always published.
It is a meaningful adjustment, but it is not a transformation. A summer-born child in the bottom quartile of raw performance will not be lifted into the qualifying band by age standardisation alone.
What this means for parents
For parents of summer-born children: the test is genuinely fair in its standardisation. You do not need to compensate for your child's age with extra preparation. The system has done that compensation for you.
For parents of autumn-born children: the older-child offset is also real, but small. It does not change the realistic preparation strategy. The test still rewards the same skills regardless of birth month.
Common misconceptions
It is sometimes claimed that summer-born children "cannot pass" the 11+. This is false — many summer-born children qualify every year, and the standardisation engine specifically exists to prevent that systematic disadvantage.
It is also sometimes claimed that older children "have an unfair advantage". This too is largely corrected for in the standardisation. Birth month should not be the dominant factor in your decision about whether to enter your child for the test.
How to find the published age adjustment
Some local authorities publish their age standardisation tables in the months after results. Most do not. Where the tables are published, they show the raw-to-scaled conversion for each age band — useful for understanding past results but not for predicting future ones.
Do not over-interpret a published table from a previous year. The conversion changes year on year based on cohort difficulty, and the prior year's table is illustrative rather than predictive.
The takeaway
Age standardisation is real, fair, and significant in design. It removes systematic age bias from 11+ results. Parents should neither over-rely on it (a summer-born uplift is not enough on its own to compensate for thin preparation) nor dismiss it (it does meaningfully equalise the playing field).
In short: prepare your child for the test. Trust the standardisation to handle their age. Both halves of that sentence matter.