O Level Grading System Explained: Grade Thresholds, A* and Percentage Uniform Marks

Ask a room of O Level students what an A* needs and most will say 90%. It doesn't — and believing it costs students twice. Some aim at a number higher than the real boundary and burn out chasing it; others panic over a mock score that would have been a comfortable A. Cambridge grades O Level in a way that is simple once you have seen it, and this guide uses Cambridge's own published figures from the June 2026 exams to show it.

Quick answer: Cambridge O Level is graded A*, A, B, C, D and E, with U for ungraded. No grade has a fixed percentage: after every exam series Cambridge sets grade thresholds — the minimum raw mark for each grade — so they move with how hard the papers were. In June 2026, O Level Mathematics D (4024) needed 173 out of 200 for an A* (86.5%), 147 for an A (73.5%) and 62 for a C (31%) on one version of the paper. The percentage printed on a statement of results is not your score but a percentage uniform mark (PUM): A* 90–100, A 80–89, B 70–79, C 60–69, D 50–59 and E 40–49.

The O Level grades at a glance

Cambridge awards grades A* to E; U means the candidate did not reach the E threshold. For a Matric (SSC) equivalence, IBCC accepts each subject at grade E or above. The two right-hand columns are explained below — and neither of them is the percentage of marks you scored.

Grade thresholds: why there are no fixed percentages

Cambridge's own definition: "A grade threshold is the minimum number of marks that a candidate needs to achieve to be awarded a particular grade." Three things follow from how Cambridge sets them:

• They are set after the exam. Cambridge sets thresholds after each examination has been taken and marked, not before.
• They hold the standard, not the number. The aim is that a grade is no more difficult and no less difficult to achieve than before. If a paper's questions turn out harder than last time, Cambridge lowers the thresholds; an easier paper raises them.
• A* exists only for the whole subject. Each paper (component) has thresholds for A to E, but grade A* does not exist as a component grade — it is set only for the syllabus as a whole, from the weighted total of your papers.

So the same raw score can earn different grades in different years, and different subjects have entirely different boundaries. That is not unfairness; it is the mechanism that makes an A in 2026 mean the same as an A in 2025.

A real example: O Level Mathematics D (4024), June 2026

Students sit two papers of 100 marks each. Cambridge sets more than one version of each paper for different parts of the world, which is why the table has two rows. These are the minimum totals out of 200 for each grade:

As percentages of the paper, on the 12 + 22 version an A* needed 86.5%, an A 73.5%, a B 52% and a C 31%. On the 13 + 23 version an A* needed 87.5% and an A 75%.

And for a single paper, the minimum marks out of 100 that June were:

Two lessons for anyone revising Mathematics. First, the A* line sat below 90% on both versions — on Papers 12 + 22, a student on 175 out of 200 had their A* with two marks to spare. Second, there is no A* column for a single paper: you cannot "get an A* on Paper 2", only on the subject.

Other subjects in the same series had different boundaries, and next June's will differ again. That is why the honest way to judge a past-paper score is against that paper's own threshold table, never against a rule of thumb.

What the percentage on your statement of results means (PUM)

Where Cambridge reports them, a statement of results shows a percentage uniform mark beside each grade. Cambridge is clear about what it is and isn't:

• It is not your total mark for the subject. It is a point on a common scale, always out of 100, that shows whether you were near the top, the middle or the bottom of your grade.
• A student on the minimum mark for an A* gets a PUM of 90. A student exactly halfway between the D and C thresholds gets 55.
• It does not change your grade; it adds information about it.
• It appears on the statement of results, not the certificate, and is not given for an ungraded result.
• It cannot be compared with the grade threshold tables, which work in raw marks.

To see how the two fit together, take the 12 + 22 Mathematics paper above. A student who scored exactly 147 out of 200 — the A threshold — would see a PUM of 80. A student on 160, halfway between the A (147) and A* (173) thresholds, would see about 85. Neither scored 80% or 85% of the marks; 160 is exactly 80%. The PUM tells you where you landed inside the grade, which is why a "low A" and a "high A" can look very different on paper.

How IBCC turns O Level grades into marks

For admissions in Pakistan, your grades become marks through IBCC equivalence, on a fixed table: A 85, B 75, C 65, D 55, E 45, while an A* is worth a figure above 90 that IBCC sets for each subject and exam session. IBCC converts the grade, not the PUM.

For Matric equivalence, a student studying in Pakistan needs eight O Levels — English, Mathematics, Urdu, Islamiyat and Pakistan Studies, plus three electives — each at grade E or above. Our IBCC equivalence guide has the A Level rules, the documents and the application steps. Those equivalence marks matter long after O Level: NUST, for example, weighs an A Level student's IBCC O Level marks at 25% of merit while they are still in their final A Level year — see our NUST NET 2027 guide.

How to use grade thresholds when you revise

1. Mark past papers with the official mark scheme, then look up that paper's thresholds — same subject, same series, same version. That tells you the grade the paper would really have earned.
2. Track the gap to the next grade, not your percentage. On the 12 + 22 Mathematics paper above, moving from a B (104) to an A (147) meant 43 more marks across two papers — about 22 a paper. A target that size can be planned week by week.
3. Average across several series. Thresholds move from year to year, so check three or four recent series to see where a subject's A and A* usually fall.
4. Read Cambridge's examiner reports. They describe where marks were lost on each question, which is often the fastest route to the next grade.
5. Finish the paper. Thresholds are set on whole-paper totals, so unanswered questions at the end are some of the most expensive marks in the exam.

How Al Noor Tuition helps

Our O Level tutors mark past papers against the right threshold table, show students exactly how many marks stand between them and the next grade, and build a plan to close that gap. Find an O Level tutor in Lahore, an O Level tutor in Karachi, or learn online from anywhere in Pakistan. For the run-up to exams, read our O Level exam preparation guide and the last three weeks revision plan; if you are still choosing subjects, start with our O and A Level subject selection guide.

Frequently asked questions

What is the grading system of Cambridge O Level?

Grades A*, A, B, C, D and E, with U for ungraded. Each grade has a minimum raw mark — a grade threshold — set by Cambridge after every exam series.

Is 90% an A* in O Level?

Not as a rule. Thresholds change by subject and series. In June 2026, O Level Mathematics D needed 173 out of 200 (86.5%) for an A* on one version of the paper and 175 (87.5%) on the other. The "90" people quote is the PUM of a student who just reached A*, not a raw percentage.

What does PUM mean on my O Level result?

Percentage uniform mark: a 0–100 scale showing where you fell inside your grade — A* 90–100, A 80–89, B 70–79, C 60–69, D 50–59, E 40–49. It is not your score and does not appear on your certificate.

Where can I find O Level grade thresholds?

On Cambridge International's website, which publishes a threshold table for each O Level syllabus after every exam series.

Is grade E a pass in O Level?

Cambridge awards grades A* to E, and U means ungraded. IBCC accepts each O Level at grade E or above for Matric equivalence, though a school or university may ask for higher grades in the subjects that matter for the course you want.

How does IBCC convert O Level grades into marks?

A 85, B 75, C 65, D 55 and E 45; an A* is worth a figure above 90 that IBCC sets for each subject and session.

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Sources: Cambridge International — "Grade threshold tables for Cambridge O Level", "Grade thresholds – June 2026: Cambridge O Level Mathematics Syllabus D (4024)" and "A guide to percentage uniform marks"; IBCC's equivalence FAQs and grade-conversion table as summarised in our IBCC guide (checked 7 October 2026). Checked on 13 October 2026.