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Why do grade boundaries change every year?

Boundaries move every year - sometimes a lot. Here’s why that’s a feature, not a fault, and what it does (and doesn’t) tell you.

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In short

Grade boundaries change from year to year mainly to reflect how difficult each year’s paper was. If a paper is harder, boundaries usually fall; if it’s easier, they can rise. The point is that the standard needed for each grade stays the same, so students aren’t advantaged or disadvantaged by the year they happened to sit the exam.

How it works

No two papers are identical in difficulty. Rather than keep the pass mark fixed and let results swing wildly, boards move the boundary so that the same quality of work earns the same grade each year. Statistical evidence about the cohort and senior-examiner judgement are used together to decide where the line sits.

Example

A subject’s grade-A boundary might be 78% one year and 72% the next. That’s usually a sign the second paper was harder - not that the grade got easier. Comparing the % of maximum mark across years is a useful way to see where the boundary sits when maximum marks differ (though it still doesn’t tell you directly how difficult the paper was).
Common misconception

A higher boundary doesn’t mean an easier grade - it usually means an easier paper. And last year’s boundary is context, not a prediction for this year.

Frequently asked questions

Why can boundaries move by several marks?

Because paper difficulty varies year to year, and the boundary is adjusted to keep the grade standard comparable. Source: Ofqual ↗

Should I use last year’s boundary as a target?

Only as rough context. Ofqual explicitly warns you shouldn’t rely on previous boundaries, because they can’t be known until this year’s marking is complete or nearly complete. Source: Ofqual ↗

Does a lower boundary mean grades are being ‘handed out’?

No. A lower boundary typically reflects a harder paper; the standard of work needed for the grade is unchanged. Source: Ofqual ↗

See it in the data

See how the boundary as a % of maximum mark has moved over four years for any subject and board.

Open a subject page →Browse all pages →

Official sources

About this guide. Produced independently by tutor2u using published guidance from Ofqual, JCQ and the awarding organisations, to explain the system clearly and put it in context. Reviewed by Jim Riley, tutor2u. How we check this guidance. Last reviewed 11 August 2026.
In Wales: this guide covers England, where exams are regulated by Ofqual. Qualifications in Wales are regulated by Qualifications Wales and awarded by WJEC - see WJEC’s grade boundaries and post-results services.

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Last checked August 2026. This is a plain-English summary of official guidance; always check the linked Ofqual, JCQ and exam-board pages for the definitive rules, which can change.

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