IGCSE Grades Explained: 9–1, A*–G and Grade Thresholds

IGCSE results use one of two grading scales: A*–G, where A* is the highest grade, or 9–1, where 9 is the highest. Pearson Edexcel International GCSEs are graded 9–1. Cambridge IGCSEs are graded A*–G around the world, with 9–1 versions of many syllabuses offered to schools in one of Cambridge's administrative zones. On either scale, the number of marks needed for each grade is not fixed in advance: it is set after every exam series and changes from one series to the next.

This guide explains how the two scales line up, which one a student will receive, how grade thresholds are set, and what tiered papers mean for the grades on offer, using real figures from the June 2026 series.

The two scales and how they line up

The A*–G scale has eight grades and the 9–1 scale has nine, so they do not match grade for grade. Instead they are tied together at three anchor points, shown in Cambridge's guide to A*–G and 9–1 grades:

In practice, then, a 7 or above corresponds to an A or above, and a 4 or above to a C or above. Away from the anchor points the scales are divided differently: grades 7, 8 and 9 together cover the range of A and A*, and grades 4, 5 and 6 cover the range of B and C. That is why a 5, for instance, has no exact letter equivalent.

Below the lowest grade on either scale is U, for ungraded. Cambridge's Mathematics 0580 syllabus, for example, explains that U means the performance did not reach the standard required for grade G, and that it appears on the statement of results but not on the certificate.

Which scale will your child receive?

• Pearson Edexcel International GCSE: 9–1. Pearson's June 2026 grade boundary tables, for example, list grades 9 to 1 and U for every International GCSE subject.
• Cambridge IGCSE: A*–G by default. Cambridge also offers 9–1 graded IGCSEs in its administrative zone 3, where schools can choose either scale, and every school can keep A*–G. The two versions are separate syllabuses with separate codes: Mathematics, for example, is 0580 on the A*–G scale and 0980 on the 9–1 scale.

The scale is settled at entry. Cambridge's rule is that once the entries deadline has passed, a candidate cannot move from a syllabus on one scale to the matching syllabus on the other; a mistaken entry has to be withdrawn and replaced before the deadline. A school can also use different boards for different subjects, so one student may finish with a mix of letters and numbers. If you are not sure which board or syllabus applies, our guide to the IGCSE exam boards explains how to tell.

Grade thresholds and grade boundaries: the marks behind a grade

Cambridge calls them grade thresholds and Pearson calls them grade boundaries, but they are the same idea: the minimum mark needed for a grade. Pearson gives a simple example in its boundary tables. If the boundary for grade 6 is 70 marks, then 70 earns a 6, and 69 earns a 5.

Cambridge explains how its thresholds are set:

• Thresholds are set after each exam has been sat and marked, never beforehand.
• In each series the aim is that every grade is no harder and no easier to achieve than it was the year before. If a paper proves harder than last time, the thresholds are lowered; if it proves easier, they are raised.
• There are thresholds for each paper (Cambridge calls papers components) and for each combination of papers that makes up the qualification. For some syllabuses, weighting factors are applied so that each paper counts as much as the syllabus says it should.
• A* is not awarded on individual papers. The A* threshold for a combination of papers is calculated from the A and B thresholds and the maximum mark.

Two consequences follow. There is no fixed percentage for any grade, so rules of thumb such as "an A* is 90%" do not hold, as the examples below show. And a past threshold tells you about that paper in that series only: it is a useful rough guide when marking a past paper, not a target for the next exam.

In regions where Cambridge provides them, statements of results for A*–G IGCSEs (not 9–1 syllabuses) also show a percentage uniform mark. It is not the raw mark, so it cannot be compared with the threshold tables.

A real example: Cambridge IGCSE Mathematics 0580, June 2026

Mathematics 0580 is tiered. According to the 0580 syllabus for 2025–2027, Core candidates sit Papers 1 and 3 and are eligible for grades C to G, while Extended candidates sit Papers 2 and 4 and are eligible for grades A* to E. The papers come in more than one version (components 21, 22 and 23 are versions of Paper 2, for instance), and each pairing gets its own thresholds. Here are three of the combinations from Cambridge's June 2026 table:

Three things stand out. A* needed 81% of the marks on one Extended pairing and 88.5% on another, in the same subject and the same series. A grade C needed about 51% on the Core papers but 45% or less on the Extended papers, which reflects the more demanding Extended papers. And the tier limits are visible in the table itself: Core combinations have no thresholds above C, and Extended combinations have none below E.

A real example: Pearson Edexcel International GCSE Mathematics A (4MA1), June 2026

Mathematics A was the only subject in Pearson's June 2026 International GCSE boundary table with separate Foundation and Higher tiers, each assessed through two papers. Its boundaries for the main papers were:

A grade 4 needed 41 marks out of 200 on the Higher tier but 125 on the Foundation tier, which shows again that a percentage on one paper says little about a grade on another. Foundation tops out at grade 5. Higher reaches down only to grade 3, so a Higher candidate who falls below that boundary has no grade 2 or 1 to drop to and is left ungraded. Pearson also published separate boundaries in the same series for an alternative set of Mathematics A papers, which differed again.

Every other subject in that table was untiered. Most had boundaries for every grade from 9 to 1, although two untiered mathematics subjects, Mathematics B and Further Pure Mathematics, had boundaries only down to grade 3.

Why tier decisions matter

Tiering is where grading turns into a decision that families can influence. Entering a student for the lower tier caps the best grade available: C on Cambridge Core Mathematics 0580, 5 on Edexcel Foundation Mathematics A. Entering for the higher tier opens the top grades but removes the safety net at the bottom. The right choice depends on what the student can reliably do on the harder papers, not on what they hope to achieve, and it is made when the student is entered for the exam.

The Cambridge IGCSE page explains how our tutors approach Core and Extended decisions, and the Pearson Edexcel International GCSE page covers the Edexcel side, including the two-tier Mathematics A.

What counts as a "pass"?

Each grade from A* to G, or from 9 to 1, is an achieved grade; only U means that no grade was awarded. When people talk about a pass, though, they usually mean the grade a university or the next course asks for. Some UK universities, for example, ask for a C at GCSE in Maths and English, and Cambridge's guide notes that on the 9–1 scale some of them accept a 4 while others ask for a 5. Always check the exact requirement of the course or institution in question.

How to read a threshold table

1. Find the right series and syllabus. Tables are published per exam series and per syllabus code, so June 2026 Mathematics 0580 is a different table from June 2026 Mathematics 0980 or from November 2025 Mathematics 0580.
2. Find the student's combination of papers. Cambridge's advice is to look for the row that matches the combination of components in the candidate's entry. That row gives the thresholds for the overall grade.
3. Compare the total, not each paper. Cambridge decides the subject grade by comparing the candidate's total across all papers, weighted as the syllabus specifies, with the thresholds for that combination. A weaker paper can be balanced by a stronger one. Pearson's tables likewise give boundaries for the overall qualification in raw marks, and for linear qualifications all the papers must be sat in the same exam session.
4. Look at the gaps between grades. On the Extended 0580 pairing 21 and 41 in June 2026, the thresholds for C, B and A were 90, 114 and 138 out of 200: 24 marks apart. Moving up a grade meant finding 24 more marks across two papers, a concrete target to plan revision around.

When you mark a past paper at home, use the table for that paper's own series and treat the result as a rough guide. Both boards publish their tables after each series: Cambridge on its grade threshold tables page, Pearson on the grade boundaries page of its qualifications website.

If you would like help working out which tier, board or grade target is realistic for a particular student, tell us about their subjects and exam board and we will give you an honest view.

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