Question 1

What are OCR 21st Century B GCSE Chemistry grade boundaries?

Accepted Answer

Grade boundaries are the minimum raw marks you need for each grade in OCR 21st Century B GCSE Chemistry (specification J258). OCR 21st Century B sets them once marking is complete for the whole cohort: senior examiners review evidence from the exam series, compare performance with previous years, and recommend where each grade boundary should sit.

The boundaries move a little from year to year, because every paper is a slightly different test. If a paper is harder than usual, the boundaries come down. If it's more accessible, they nudge up. The aim is that a grade represents the same standard whichever year you happened to sit the exam, even though the raw mark needed will vary between series.

Question 2

Why do the OCR 21st Century B Chemistry boundaries change every year?

Accepted Answer

Because every paper is a slightly different test. Once marking is complete, senior examiners at OCR 21st Century B look at how the cohort performed against previous cohorts and evidence from senior marking, then set boundaries so that a grade means roughly the same standard year on year.

A boundary shifting down doesn't mean the subject got easier or the cohort got weaker; it usually means the paper was slightly harder to score marks on than the previous year, and the boundary moved to compensate. This is why you shouldn't fix a specific mark in your head as 'the 9': aim for the top end of the range and you'll comfortably clear whichever boundary lands.

Question 3

When are the OCR 21st Century B GCSE Chemistry grade boundaries published?

Accepted Answer

OCR 21st Century B normally publishes GCSE grade boundaries at 8am on GCSE results day, alongside the grades themselves. They land as one large PDF covering every GCSE subject that series.

We update this page shortly after OCR 21st Century B releases the boundaries, so you can look up your total against the fresh boundaries and see what grade it would have earned.

Question 4

What mark do I need for a grade 9 in OCR 21st Century B GCSE Chemistry?

Accepted Answer

It depends on the year, because OCR 21st Century B sets the boundaries once the cohort has been marked. In recent series, the grade 9 boundary for OCR 21st Century B GCSE Chemistry has typically landed around 70-75% of the maximum marks, but the exact percentage varies year to year.

For revision, aim to comfortably clear the top-end of that range on past papers rather than fixing a specific mark. That way you're insulated against a year when boundaries shift up.

Question 5

How should I use these boundaries when I'm revising?

Accepted Answer

There are two ways worth building into your routine.

**Score your past papers realistically.** Sit a paper timed, mark it against the official mark scheme, then check your total against the boundary for that year. That gives you a much clearer sense of where you really are than a rough self-estimate.

**Focus your revision on weaker topics.** If you're consistently landing 5-10 marks short of your target grade, work out which topics those marks are being dropped on. A [OCR 21st Century B Chemistry revision course](https://cognito.org/courses/gcse/chemistry/ocr-b) can help you plug the specific gaps rather than re-revising what you already know.

Question 6

Can I use Cognito for OCR 21st Century B GCSE Chemistry exam practice?

Accepted Answer

Yes. Our [GCSE Chemistry (OCR 21st Century B) course](https://cognito.org/courses/gcse/chemistry/ocr-b) covers the whole specification with concise notes, quizzes and full past papers. You can score your attempts against the mark scheme and cross-reference your totals to the boundaries on this page.

If you're closer to results day, our [past-papers library](https://cognito.org/past-papers) has the full set of OCR 21st Century B papers so you can time yourself against the real thing.

Series	Max	Grade 9	Grade 8	Grade 7	Grade 6	Grade 5	Grade 4	Grade 3
Jun 2025Latest	180	141	127	114	94	75	56	46
Jun 2024	180	128	114	100	81	63	45	36
Jun 2023	180	131	114	98	79	60	41	31
Jun 2022	180	125	109	93	75	58	41	32
Jun 2019	180	128	113	99	83	67	52	44
Jun 2018	180	129	114	100	83	66	50	34

GCSE Chemistry OCR 21st Century (B) Grade Boundaries

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