Which grade boundaries should you use for IGCSE mocks?
Use the grade threshold table from the same exam series and the same paper variant your mock paper came from. Convert each student's raw component marks using Cambridge's weighting factors, then compare the total with that series' overall syllabus thresholds. Cambridge publishes a guide for exactly this. The result is an estimate, not a prediction, and you should report it that way.
This is one of the most common questions in IGCSE departments every mock season, and there is a lot of guesswork around it. Here is the method Cambridge itself describes, with the mistakes to avoid.
Why can't I just use last year's boundaries?
Because boundaries move. Cambridge says grade thresholds vary slightly from year to year. They are set using statistical evidence and examiner judgement about how hard each paper turned out to be.
They also vary between variants in the same series. Cambridge sets different paper variants for different time zones. In June 2026, IGCSE Mathematics 0580 showed how big the gaps can be:
| June 2026, 0580 Extended | Variant 1 (21 + 41) | Variant 2 (22 + 42) | Variant 3 (23 + 43) |
|---|---|---|---|
| Paper 2, grade C threshold (out of 100) | 40 | 41 | 47 |
| Overall grade A threshold (out of 200) | 138 | 154 | 154 |
| Overall grade C threshold (out of 200) | 90 | 87 | 94 |
A total of 140/200 was an A on variant 1 but a B on variants 2 and 3. Same syllabus, same month.
So if your mock used 0580 Paper 22 from June 2025, use the June 2025 thresholds for variant 22, not this year's, and not variant 21.
Step by step: converting mock marks into a grade
Cambridge's Guide to converting component marks into syllabus grades (section 2) describes the method for mock exams:
- Record each student's raw mark per component, for example Paper 2 = 61/100 and Paper 4 = 68/100 for 0580 Extended.
- Adjust if you need to. If you shortened a paper or left out a question, scale the raw mark up to the full paper total. Be transparent about it.
- Apply the component weighting. The conversion guide explains how to scale each component so its share of the total matches the syllabus weighting. The threshold table shows the "maximum weighted mark" for each combination, which you can use to check your arithmetic. For 0580 Extended, both papers are out of 100 and weighted 50/50, so no scaling is needed.
- Add the weighted marks to get a syllabus total.
- Compare the total with the overall syllabus thresholds for the right component combination ("option") in that series.
Grade threshold tables are on the Cambridge website for recent series. The full archive is on the School Support Hub for registered schools.
Worked example: 0580 Extended, June 2026 variant 1
A student sat Papers 21 and 41 from June 2026 as a mock.
| Paper 21 | Paper 41 | |
|---|---|---|
| Raw mark | 61 / 100 | 68 / 100 |
| Weighted mark (both papers are 50%, so the combined maximum is 200) | 61 | 68 |
The weighted total is 129/200. The June 2026 overall thresholds for components 21 + 41 are A* = 162, A = 138, B = 114 and C = 90. The student's mock grade is B, nine marks short of an A.
For other syllabuses, components are often weighted differently. Always check the maximum weighted mark in the threshold table.
Do thresholds work the same for 9–1 syllabuses?
Cambridge's 9–1 syllabuses (such as 0980 Maths, 0970 Biology and 0990 First Language English) have the same assessment as their A*–G versions. Only the grading differs. Cambridge sets the standard at the bottom of grade 7 to match the bottom of A, grade 4 to match C and grade 1 to match G. See 9–1 vs A*–G for teachers. Grades 8, 6, 5, 3 and 2 are set arithmetically between them. Use the 9–1 syllabus's own threshold table, not a converted A*–G table.
What about Core and Extended?
Core and Extended candidates sit different components, so they have separate thresholds.
- Sciences (0610, 0620, 0625). Core candidates can reach grades C–G. Extended candidates can reach A*–G.
- Mathematics 0580. Core reaches C–G. Extended reaches A*–E.
A Core student who scores very highly on a mock can't be awarded an A, whatever the raw mark. That is a useful conversation when deciding tier entries.
Can I use component thresholds on their own?
You can use them as a guide for a single paper. But there is no A* at component level: Cambridge only awards A* on the overall syllabus total. If you mark only Paper 4 as a mid-year test, report "grade A standard on this paper", not "A*".
How should I report mock grades?
- Call it an estimate. "Based on June 2025 thresholds, this score would have been a B."
- Show the margin. A student two marks below a boundary and one twenty marks below are in different places. Report the raw total next to the grade.
- Remember conditions differ. Mocks are often sat earlier in the course, with less revision. Many departments note this alongside the grade.
- Don't mark towards the boundary. Cambridge's Generic Marking Principles say marks are awarded against the mark scheme only, never with grade thresholds in mind. Mark first, then apply thresholds.
Where AI fits in
The slow part of mock season isn't the threshold arithmetic. It's marking 60 to 150 scripts per teacher accurately enough for the grades to mean something. The Learning Mate marks handwritten scripts question by question against your mark scheme. It exports marks to Excel, so you can run the threshold conversion across a whole cohort in minutes. Every mark stays editable until you release it.
FAQ
What grade boundaries should I use for an IGCSE mock?
Use the grade threshold table from the same series and variant as the past paper you set, for example June 2025 variant 22. Apply the weighting factors and the overall syllabus thresholds for the right component option.
Do IGCSE grade boundaries change every year?
Yes. Cambridge says thresholds vary slightly from year to year, and they also differ between paper variants within the same series.
Is there an A* on individual IGCSE papers?
No. Cambridge does not set an A* threshold at component level. A* is only awarded on the overall syllabus total.
How do 9–1 grades compare to A*–G for IGCSE?
Cambridge aligns grade 7 with A, grade 4 with C and grade 1 with G. The other grades are spaced arithmetically between them.
Where do I find past IGCSE grade threshold tables?
Recent tables are on the Cambridge International website. Registered schools can find older series on the School Support Hub.
Sources
- Cambridge, Guide to converting component marks into syllabus grades: cambridgeinternational.org
- Cambridge IGCSE grade threshold tables: cambridgeinternational.org
- 0580 June 2026 grade threshold table: cambridgeinternational.org
- Cambridge, Marking and grading: cambridgeinternational.org
- Cambridge, How 9–1 grading works: cambridgeinternational.org