Mock grades often come out lower. We checked five years of official GCSE grade boundaries to show how much the year your school picks changes your grade.
Mock papers are meant to be like the real exam, but mock grades often come out lower. You usually sit a mock before the whole course has been taught, with less time to revise, and your school chooses which year's grade boundaries turn your marks into a grade. In our study of official GCSE boundaries, that choice alone changed the grade for nearly half of all possible scores in a typical subject and tier, usually by one grade. Treat a mock grade as an estimate and use the marks you lost to plan your revision.
Is part of the course missing when you sit a mock?
Usually, yes. Ofqual's guidance to schools on mocks says students should normally only be assessed on content they have been taught so far, and it encourages schools to hold these assessments in the first half of the academic year where possible. A Year 11 mock in the autumn or in January comes months before the course ends. That affects your result in one of two ways. If your school leaves out what you haven't been taught, the mock covers fewer topics than the June exam and can't tell you how you'd do on the rest. If it uses a full past paper, some questions may be on topics you haven't reached yet, which pulls your mark down. Ask your teacher which it was.
How do schools turn mock marks into a grade?
Your teacher marks the paper with the mark scheme, adds up the total and turns it into a grade with a set of grade boundaries. There is no official set of mock boundaries. Ofqual explains that new grade boundaries are set each year to reflect the difficulty of each paper, so every June series has its own. Your school chooses which year to use. A school may also scale the marks or set its own boundaries. Ofqual's guidance asks schools not to use the boundaries from autumn 2020, autumn 2021 or summer 2022, when there was “greater leniency in grade boundaries that is not normally applied in exams”. It says papers from 2019 and earlier, and from 2023 onwards, are the most useful guide to the standard needed for each grade. Those are the years we compared below.
Why do exam conditions make a mock feel harder?
A mock may be the first time you sit full papers back to back. Ofqual's guidance asks schools to supervise these assessments, keep books and revision notes away, and time them the same way as the real exam. That is harder than a class test on a topic you finished last week. You have to recall months of work at once, keep to time and keep going through questions you find hard. Those are skills, and they improve with practice. If your mock showed that you ran out of time, sit full papers against the clock before the summer.
How much does the boundary year change your grade?
We measured the choice of boundary year on its own. Using the official boundaries from AQA, Pearson Edexcel and OCR for five June series, we worked out the grade at every whole percentage from 0 to 100 under each year's boundaries, for 44 GCSE subject and tier combinations, and counted how often it changed. The method is at the end of this guide. In a typical subject and tier (the median of the 44), 46.5% of possible scores got a different grade depending on the year used. The lowest was 14.9% in AQA Chemistry Foundation and the highest was 63.4% in OCR Chemistry A Higher. The change was usually one grade. Leaving out scores that fall below the lowest grade in any year, at least one score moved by two grades in 15 of the 44, and by three in OCR Chemistry A Higher: 75% is a 9 with 2019 boundaries, an 8 with 2023, a 7 with 2024 or 2025, and a 6 with 2026. The table shows a selection. The grade columns give the lowest and highest percentage of the total marks that grade needed across the five years. A wide gap means a mock grade in that subject depends heavily on the year your school picks. On Higher tier, a low score can even be a U one year and a 4 another: in AQA Physics Higher, 30% is a 4 with 2019 boundaries and a U with 2025.
How much the boundary year changes a GCSE grade (June 2019, 2023, 2024, 2025 and 2026)
Board, subject and tier
Scores from 0 to 100% that change grade with the year
Grade 4 needs
Grade 7 needs
AQA Maths, Higher
62.4%
17.9% to 26.2%
56.7% to 69.2%
AQA Maths, Foundation
54.5%
50.8% to 66.7%
Not available on Foundation
Edexcel Maths, Higher
45.5%
17.5% to 22.1%
57.1% to 65.0%
OCR Maths, Higher
57.4%
13.0% to 22.7%
48.0% to 57.0%
AQA Combined Science Trilogy, Higher (4-4 and 7-7)
52.5%
20.7% to 26.4%
47.4% to 54.3%
Edexcel Combined Science, Higher (4-4 and 7-7)
50.5%
26.1% to 30.0%
56.7% to 63.1%
AQA Biology, Higher
29.7%
24.0% to 28.0%
52.0% to 56.5%
AQA Physics, Higher
55.4%
25.5% to 35.0%
54.0% to 64.0%
OCR Chemistry A, Higher
63.4%
31.1% to 42.2%
58.3% to 77.2%
AQA English Language
27.7%
44.4% to 47.5%
62.5% to 67.5%
Edexcel English Language
35.6%
50.0% to 54.4%
70.6% to 72.5%
How do you work out a grade from your mock marks?
Here is a worked example with AQA GCSE Maths Higher, which has three papers of 80 marks, 240 in total. Say you score 42, 38 and 46 in your mocks. That is 126 out of 240, or 52.5%. The table shows what 126 marks gets with each year's boundaries.
Worked example: 126 out of 240 in AQA GCSE Maths Higher
Boundaries from
Grade 5 needs
Grade 6 needs
Grade 7 needs
126 marks is a
June 2019
74
105
136
6
June 2023
92
125
158
6
June 2024
95
129
163
5
June 2025
96
130
164
5
June 2026
97
131
166
5
How do you check your own mock grade?
With last summer's boundaries, 126 is a 5, five marks short of a 6. With 2019 or 2023 boundaries it is a 6. Your answers are the same in every row. The fairest way to describe that result is a high 5 or a low 6. Do the same with your own marks.
Add up your marks across every paper in the mock.
Check the real total. If your mock was shorter than the real exam, work out your percentage and take that percentage of the real total. This assumes you would score the same on the papers you didn't sit.
Find the boundaries for your board, specification code and tier.
Your grade is the highest grade whose boundary you reached.
Count how many marks you are from the boundaries above and below, then repeat with a second recent year. If the grade changes, your mock grade is a range.
Treat it as a rough position. The marks you lost, and why you lost them, tell you far more than the grade.
Ask your teacher which year's boundaries were used and whether the marks were scaled.
Look at the gap to the next grade. Three marks below a boundary is very different from thirty.
Sort every lost mark into knowledge, exam technique, timing or misreading, and fix the biggest group first.
When you sit a past paper at home, grade it with the boundaries from the same June as the paper, because those were set for that paper.
For a paper written by your school or anyone else, no year's boundaries fit exactly, so any grade from it is an estimate.
Practise again before the real thing. Revise Right runs free mocks, and the next round is in December. They are original practice papers written by Revise Right, timed, and marked by AI against a mark scheme. They are not exam-board papers and they are not examiner-approved. Your results show your score as a percentage, an estimated grade worked out with last summer's grade boundaries, and a topic-by-topic breakdown. Read that grade as an estimate too.
Yes, in the same basic way. A-Level papers also get new grade boundaries each June, and Ofqual says boundaries change each year to reflect any differences in the demand of the question papers. Our study covered GCSE only, so we can't put numbers on A-Level. The same checks apply: ask which year's boundaries were used, and read the grade as a range. A Year 13 mock held in the first half of the year, as Ofqual encourages, also comes before the course is finished. Ofqual's guidance notes that mock results can inform predicted grades, including UCAS predictions, so ask your teacher how your mock will be used.
How did we run the study?
Every figure in this guide comes from the boards' own documents, listed in the sources below.
Boards and subjects: AQA, Pearson Edexcel and OCR; GCSE Maths, Combined Science, Biology, Chemistry, Physics and English Language; every specification and tier, 44 combinations in all.
Years: June 2019, 2023, 2024, 2025 and 2026. There were no summer exams in 2020 or 2021. We kept June 2022 out of the comparison because Ofqual set grading that year at a midpoint between 2019 and 2021, and describes greater leniency in its boundaries.
Boundaries: the whole-subject raw-mark boundaries in each board's official June document, as a percentage of the maximum mark. Combined Science uses its double grades, such as 7-6.
Rule: at each whole percentage from 0 to 100, the grade is the highest one whose boundary that score reaches. A score depends on the year if it gets two or more different grades across the five years.
Coverage: 219 of 220 boundary tables. Edexcel's English Language 2.0 has no June 2019 boundaries, so it uses four years.
Limits: this measures the boundary year only. A mock sat midway through the course covers fewer topics than the real exam, and schools may scale marks or set their own boundaries, so a real mock grade can move for reasons this study doesn't capture.
Sources
Ofqual: guidance on collecting evidence of student performance to ensure resilience in the qualifications system: How schools should run and mark mocks: taught content only, the first half of the year where possible, timed and supervised, and no boundaries from 2020 to 2022 (updated 4 March 2025). Ofqual: GCSE 9 to 1 grade scale explained: Why new grade boundaries are set each year to reflect the difficulty of each paper. Ofqual blog: exam results 2022, 10 things to know about GCSE, AS and A level grades: Why 2022 was graded at a midpoint between 2019 and 2021, and why GCSE, AS and A level boundaries change each year with the demand of the papers. AQA: GCSE grade boundaries, June 2019: AQA's official qualification-level raw-mark grade boundaries for every GCSE in the June 2019 series, used in our boundary-year study. AQA: GCSE grade boundaries, June 2023: AQA's official qualification-level raw-mark grade boundaries for every GCSE in the June 2023 series, used in our boundary-year study. AQA: GCSE grade boundaries, June 2024: AQA's official qualification-level raw-mark grade boundaries for every GCSE in the June 2024 series, used in our boundary-year study. AQA: GCSE grade boundaries, June 2025: AQA's official qualification-level raw-mark grade boundaries for every GCSE in the June 2025 series, used in our boundary-year study. AQA: GCSE grade boundaries, June 2026: AQA's official qualification-level raw-mark grade boundaries for every GCSE in the June 2026 series, used in our boundary-year study. Pearson Edexcel: GCSE grade boundaries, June 2019: Pearson Edexcel's official qualification-level raw-mark grade boundaries for every GCSE in the June 2019 series, used in our boundary-year study. Pearson Edexcel: GCSE grade boundaries, June 2023: Pearson Edexcel's official qualification-level raw-mark grade boundaries for every GCSE in the June 2023 series, used in our boundary-year study. Pearson Edexcel: GCSE grade boundaries, June 2024: Pearson Edexcel's official qualification-level raw-mark grade boundaries for every GCSE in the June 2024 series, used in our boundary-year study. Pearson Edexcel: GCSE grade boundaries, June 2025: Pearson Edexcel's official qualification-level raw-mark grade boundaries for every GCSE in the June 2025 series, used in our boundary-year study. Pearson Edexcel: GCSE grade boundaries, June 2026: Pearson Edexcel's official qualification-level raw-mark grade boundaries for every GCSE in the June 2026 series, used in our boundary-year study. OCR: GCSE grade boundaries, June 2019: OCR's official qualification-level raw-mark grade boundaries for every GCSE in the June 2019 series, used in our boundary-year study. OCR: GCSE grade boundaries, June 2023: OCR's official qualification-level raw-mark grade boundaries for every GCSE in the June 2023 series, used in our boundary-year study. OCR: GCSE grade boundaries, June 2024: OCR's official qualification-level raw-mark grade boundaries for every GCSE in the June 2024 series, used in our boundary-year study. OCR: GCSE grade boundaries, June 2025: OCR's official qualification-level raw-mark grade boundaries for every GCSE in the June 2025 series, used in our boundary-year study. OCR: GCSE grade boundaries, June 2026: OCR's official qualification-level raw-mark grade boundaries for every GCSE in the June 2026 series, used in our boundary-year study.
Are GCSE mocks marked more harshly than the real exam?
Ofqual asks teachers to mark mocks in line with the exam board's published mark schemes, so the marking itself should match the real exam. The grade can still come out lower because of untaught topics, less revision time and the year of boundaries your school picks.
Do students do better in the real exam than in their mocks?
We looked for published UK data that follows students from their mock grades to their final grades and didn't find any, so be wary of claims that most students go up a set number of grades. By June you will have been taught the whole course and had months more to revise. How much you improve depends on what you do with the marks you lost.
Which grade boundaries do schools use for mocks?
Each school chooses. Ofqual's guidance asks schools not to use the boundaries from autumn 2020, autumn 2021 or summer 2022, and says papers from 2019 and earlier, and from 2023 onwards, are the most useful. If you grade a past paper yourself, use the boundaries from the same June as the paper, because each year's boundaries were set for that paper.
How close is a mock grade to the real GCSE grade?
Nobody can say for one student. A mock grade comes from one sitting, part of the course and one year's boundaries. Read it as a range: if you are within a few marks of a boundary, you could be either grade. The topic-by-topic picture of where you lost marks is more useful than the number.