Cambridge IGCSE Grade Thresholds Explained: How They Actually Work

If you have ever finished a Cambridge IGCSE exam and immediately searched for the expected threshold, you are not alone. But grade thresholds are often misunderstood. A Cambridge grade threshold is the minimum mark needed to achieve a particular grade in a paper or in the overall subject. It is not a fixed percentage that stays the same every year, and an A* is not automatically 90% or any other universal percentage. Cambridge sets thresholds after an examination has been taken and marked. If a paper is found to have been more difficult than the comparable paper in another series, the threshold may be lower; if it was easier, the threshold may be higher. The aim is to keep the standard required for each grade comparable from one series to another.

What is a grade threshold?

A grade threshold is the minimum number of marks needed for a grade. If the overall A threshold for a particular subject option is 150, a candidate needs at least 150 weighted marks to reach that boundary. Someone below 150 may still meet the threshold for the next grade down. Cambridge publishes official grade-threshold tables after each exam series. These documents contain thresholds for individual components and, separately, for the combinations of components that make up the complete qualification.

Why do Cambridge grade thresholds change?

Examination papers cannot be made identical in difficulty from one series to another. A Physics or Biology paper in one session may contain questions that candidates generally find harder than the corresponding paper from another session. Cambridge explains that thresholds are adjusted after marking so that it is no more difficult and no less difficult to obtain a grade than in the previous year. That is why comparing raw percentages between exam series can be misleading: the mark boundary may move even though the awarding standard is intended to remain comparable.

Is 80% always an A* in IGCSE?

No. There is no universal rule that 80%, 85%, 90% or another fixed percentage always equals an A*.

For example, in Cambridge IGCSE Biology (0610), March 2026, the Extended combination of Components 22, 42 and 52 had a maximum weighted mark of 200. The published A threshold was 171, while the A threshold was 150. In that specific combination, 171/200 is 85.5%. That figure belongs to that subject, series and option; it is not a general Cambridge A percentage.

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Component thresholds and overall syllabus thresholds are different

This is one of the most important distinctions in a threshold document. Component grade thresholds apply to individual papers. Syllabus grade thresholds apply to the complete combination of papers that makes up your qualification. Your final IGCSE grade is based on the overall syllabus result, not simply on receiving the same imagined letter grade in every paper. Cambridge first establishes component thresholds and then combines them, applying weighting where the syllabus requires it, to produce thresholds for the available component combinations.

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Why do different component combinations appear?

Students do not necessarily take exactly the same papers. Some subjects have different variants, Core and Extended routes, or alternative component combinations. The threshold table therefore contains multiple rows. To find the threshold that applies to you, match the combination of components you actually took. A Biology candidate who sat Components 22, 42 and 52 should use that row, not a row containing 21, 41 and 61 simply because both belong to syllabus 0610. The subject code alone is not always enough.

What does weighting mean?

The raw maximum marks printed on the papers do not always determine their contribution to the final qualification directly. For some syllabuses, Cambridge applies weighting factors so that each component contributes the proportion stated in the syllabus. This means that simply adding the raw marks from your papers may not produce the number that should be compared with the syllabus threshold. The relevant comparison is your overall result after any required weighting against the threshold for your component combination.

How is your final grade worked out?

At a simplified level, the process is: you sit the required components; each component is marked; any required weighting is applied; the component marks are combined; and the resulting total is compared with the syllabus thresholds for your component combination. Cambridge describes the syllabus grade in the same way: the candidate's total across all papers, weighted as specified in the syllabus, is compared with the thresholds for the combination of components taken.

How does A* work?

A causes particular confusion because students often try to find an A boundary for each individual paper. Cambridge explicitly states that A does not exist as a component grade. The A threshold is calculated for the overall combination of components, relative to the A and B thresholds and the maximum mark. So if an individual component table does not show an A boundary, nothing is missing. A belongs at the syllabus-combination level.

A real Cambridge example

The March 2026 Cambridge IGCSE Biology (0610) table provides a clear example. For the Extended combination 22, 42 and 52, the maximum weighted mark was 200. The published thresholds were 171 for A, 150 for A, 129 for B and 109 for C. If a candidate's weighted total were 156, that total would sit above the A threshold of 150 but below the A threshold of 171. The candidate would therefore fall within the A range for that specific combination and exam series.

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Do thresholds differ by variant?

They can. Different variants use different examination papers, and the threshold document may show separate combinations for those routes. Overall thresholds are not guaranteed to be identical across variants. That is why a threshold screenshot shared by a student in another administrative zone should not be used automatically. Check the exact component numbers first.

When are grade thresholds decided?

Thresholds are set after the papers have been sat and marked. Cambridge says it cannot publish them in advance because the thresholds are determined during the grading process. Students and teachers can compare previous series or discuss how difficult a paper felt, but those estimates are not official thresholds. Claims about an exact future boundary should therefore be treated cautiously until Cambridge publishes the table.

Can you predict the next Cambridge thresholds?

Previous thresholds can provide historical context, but they cannot reliably tell you the exact next boundary. The next paper is different, candidate performance may differ and Cambridge reviews the evidence after marking. A statement such as "last year an A* was 160, so this year it will probably be about 160" ignores why thresholds exist in the first place.

Where can you find official IGCSE grade thresholds?

Use Cambridge International's official IGCSE Grade Threshold Tables page and select the correct exam series and syllabus. When you open a threshold document, check the subject and syllabus code, the series, your component numbers, the correct option row and whether you are reading component or syllabus thresholds. That simple check prevents most of the confusion caused by isolated screenshots or percentage claims online.

The main thing to remember

Cambridge grade thresholds are not fixed percentages chosen before the exam. They are boundaries set after marking to determine the minimum marks required for each grade while maintaining standards between exam series. A threshold can change from one series to another. Your overall syllabus threshold matters for your final grade. Weighting may affect how component marks are combined. A* is an overall syllabus grade, not an individual component grade. And there is no universal percentage that always guarantees a particular Cambridge grade.