A-level results: the percentage-point trap in the headlines

A-level results arrive the same way every year: as a shower of percentages. The share of entries awarded top grades, the proportion who passed, the year-on-year change, all of it delivered in figures with a per cent sign attached. This year the headline number was that A and A* grades edged up again, to 28.5 per cent of entries across England, Wales and Northern Ireland, from 28.3 per cent last year. It is a tiny move, and it is a perfect example of the one mistake that slips into results coverage every single August.

Per cent and percentage points are not the same thing

Top grades went from 28.3 per cent to 28.5 per cent. It is tempting to call that a rise of "0.2 per cent". It is not. It is a rise of 0.2 percentage points, which is a different measurement, and the gap between the two is the whole story.

A percentage point is just the plain difference between two percentages: 28.5 minus 28.3 is 0.2 percentage points. A per cent change asks something else entirely: how big is that step relative to where you started? Nought point two on top of 28.3 is 0.2 divided by 28.3, which comes out at about 0.7 per cent. So the same movement is "up 0.2 percentage points" or "up roughly 0.7 per cent" depending on which question you are answering, and both are far smaller than the "0.2 per cent" a careless summary might reach for. If you want to see the relative version for any pair of figures, the percentage change calculator does it in a step, and it is the quickest way to stop a wobble being dressed up as a swing.

What "top grades" actually measures

The figure everyone reaches for is the percentage of entries graded A or A*. Notice it is a share of entries, not of students: a pupil sitting three subjects counts three times, once per paper. Around 40 per cent of 18-year-olds in England take A-levels each summer, so the number describes how the grades fell across all those papers, not how many teenagers had a good day.

That share has had a turbulent few years. In the last summer of normal exams before the pandemic, roughly a quarter of entries earned an A or A*. When exams were cancelled and grades came from teacher assessment instead, the figure leapt, peaking at around 44 to 45 per cent in 2021. Since then the regulator has steered grading back towards the old standard, which is why the top-grade share now sits in the high twenties. This year's students are part of that story in another way too: most of them were in Year 7 and Year 8 during the 2020 and 2021 disruption. Read 28.5 per cent on its own and you miss all of that; the meaning is in the comparison, which is exactly what a percentage change is built to show.

The base underneath the percentage

A percentage is only half a fact. The other half is what it is a percentage of, and that base moves too. The number of entries rises and falls with the size of the eighteen-year-old population and with which subjects are popular, so an identical percentage can sit on top of very different totals from one year to the next. That matters this summer, because alongside the grades a record number of students were confirmed a place at university, with around 41 per cent of UK 18-year-olds having applied by the end of June. A steady percentage of a larger cohort still means more people through the door. Whenever a percentage is quoted with no count behind it, that is the question worth asking: per cent of how many?

UCAS points play a different game

Results day comes with a second number system that trips people up in the opposite direction: UCAS tariff points. These are not percentages at all. Each grade is worth a fixed points score, and an offer is usually written as a points total or a run of grades. It is easy to assume points scale like percentages, but they do not map onto them neatly, which is why turning an offer into the grades that satisfy it is awkward to do in your head. The UCAS points calculator converts a set of grades into a tariff total and back, which earns its keep during clearing, when an offer is quoted one way and your results are in the other.

Behind the percentages sit real papers

It is easy to treat the national figures as if they descend from on high, but every one of them is built from individual scripts and grade boundaries. That was in sharp focus this year, with the regulator in England saying it was closely monitoring the marking of an A-level maths paper that students and parents argued was noticeably harder than usual. It is a useful reminder that a grade boundary is itself a percentage decision, quietly nudged so that a tougher paper does not unfairly punish the students who sat it. The smooth national percentages are the sum of thousands of those small judgements.

Reading the day well

None of this changes what the results mean for the student holding the envelope. But it changes how much you should trust a headline. When the coverage says grades are "up" or "down", check three things: whether the change is in percentage points or per cent, what the base is, and which year is being used for comparison. Do that and the numbers stop being a blur and start telling you something real. Everything else about the day, the celebrations and the clearing and the retakes, is easier to think about once the maths is straight.

Grade figures are for England, Wales and Northern Ireland, describe the proportion of entries rather than students, and are drawn from this year's results reporting and published JCQ statistics. This is general information about how the figures work, not results advice.