Your O Level statement of results lists two things beside each subject: a letter grade and a number. Many families read that number as the percentage of marks scored. It isn’t, and that mix-up causes a lot of confusion on results day.
Here is the short answer. The O Level grading system used by Cambridge awards grades from A* (highest) to E, with U meaning ungraded. Each grade is decided by grade thresholds, the minimum marks needed for that grade, which change from one exam series to the next. The number beside your grade is a percentage uniform mark (PUM), which shows where your result sits within that grade.
This guide explains the Cambridge O Level grading system using real figures from Cambridge’s June 2026 threshold tables. It also covers what the system means for students in Pakistan and how to use it while preparing.
What Is the O Level Grading System?
Cambridge O Level uses six pass grades, A* to E. A U (ungraded) result means the total fell below the E threshold. Each grade also has a fixed PUM band, set out in Cambridge’s guide to percentage uniform marks.
| Grade | PUM range | How it is generally read |
|---|---|---|
| A* | 90–100 | Outstanding command of the whole syllabus |
| A | 80–89 | Excellent, consistent performance |
| B | 70–79 | Very good understanding with a few gaps |
| C | 60–69 | Sound grasp of the core content |
| D | 50–59 | Basic understanding with clear gaps |
| E | 40–49 | Minimum pass grade |
| U | None | Ungraded; no PUM is reported |
Your certificate shows only the grade. The PUM appears on the statement of results.
What Is A* in O Level?
A* is the highest grade Cambridge awards at O Level. It is decided only at subject level: Cambridge’s threshold tables state that A* does not exist for an individual component. You cannot earn an A* on Paper 1 alone; it comes from your weighted total across all the papers in that subject.
There is also no fixed percentage for A*. The mark needed changes by subject and by series, as the threshold examples in the next section show. A total that lands exactly on the A* threshold gives a PUM of 90, the bottom of the A* band.
In practice, this means one weak paper can pull an otherwise strong total below the A* line, because the line usually sits high.
O Level Grade Thresholds: Why the Marks Needed Change
Grade thresholds, often called grade boundaries, are the minimum marks needed for each grade in a particular exam series. Cambridge explains that they vary with the demand of the question paper and are not adjusted to the ability of the students who sat it.
That is why the same score can earn different grades in different years. Here are the June 2026 A* and C thresholds for three popular subjects:
| Subject (syllabus, papers) | Max mark | A* | C |
|---|---|---|---|
| Mathematics D (4024), papers 12 + 22 | 200 | 173 | 62 |
| Chemistry (5070), papers 11 + 21 + 31 | 200 | 160 | 67 |
| English Language (1123), papers 11 + 21 | 100 | 80 | 56 |
Thresholds can even differ within one session. Mathematics D students on papers 13 + 23 needed 175, not 173, for A*. Because thresholds are set after marking, nobody knows the exact boundaries while sitting the exam.
Percentage Uniform Marks: The Number Beside Your Grade
Percentage uniform marks put every syllabus on the same 0–100 scale. They show whether a result sits near the top, middle or bottom of its grade band. Keep three points in mind:
- PUM is not your raw percentage. Cambridge states that it is not the total mark achieved for the syllabus.
- It depends on two things: your total mark and where the grade thresholds fell in that series.
- It never changes your grade. A PUM of 89 is still an A, however close it is to the A* band.
You also cannot read PUMs against the grade threshold tables, because the two use different scales.
Raw Marks vs PUM: A Worked Example
Suppose a student sits Mathematics D (4024), papers 12 + 22, in June 2026 and scores 160 out of 200. That is 80% of the raw marks.
- 160 is above the A threshold (147) but below A* (173), so the grade is A.
- The A band runs from 147 to 172, which maps to PUMs of 80 to 89.
- 160 sits about halfway through that band, so the PUM would be roughly 85.
So the raw score is 80%, the PUM is about 85, and the grade is A. Cambridge does not publish a simple formula, so treat this as an estimate. Its own guide gives a similar illustration: a mark halfway between the D and C thresholds gives a PUM of 55.
The O Level Grading System in Pakistan
Students in Pakistan sit the same Cambridge papers and grading scale as candidates worldwide, usually in the May/June or October/November series. For the June 2026 series, Cambridge released O Level results on 18 August 2026.
Grades matter again when you move to FSc, ICS or a local university. Pakistani institutions usually ask O Level students for an IBCC equivalence certificate, which converts grades into Matric-equivalent marks. According to the IBCC grade conversion page:
- A = 85, B = 75, C = 65, D = 55 and E = 45 marks
- A* = above 90, with subject-wise marks listed for sessions from 2021 onwards
Because IBCC works from the grade, your letter grade matters more here than your PUM. Rules can change, so check IBCC’s website before applying.
How to Use Grade Thresholds When You Prepare
Understanding grading is useful only if it changes how you study. Here is a practical way to apply it:
- Collect past threshold tables from Cambridge for each subject and note the A*, A and B lines over the last few series.
- Mark timed past papers strictly with the official mark schemes, then compare your total with those thresholds to estimate a grade.
- Track the gap, not the percentage. “Twelve marks short of A* in Chemistry” is a clearer target than “I’m at 75%”.
- Find the paper that costs you most. Since grades come from the combined total, lifting your weakest paper often moves the grade fastest.
- Compare like with like. Each threshold row applies to one combination of papers, so use the row that matches yours.
Parents can use the same approach to ask better questions: which paper is weakest, and how far is it from the next grade? For a weekly routine, see our study plan for O Level students before exams and the common mistakes O Level students make before exams.
Common Misunderstandings About O Level Grades
- “A PUM of 85 means I scored 85%.” Not necessarily. As the worked example shows, PUM and raw percentage sit on different scales.
- “90% always gets an A.”* The required mark varies by subject. In Additional Mathematics (4037), one June 2026 route needed 141 out of 160 (about 88%) for A*.
- “Last year’s boundaries tell me exactly what I need.” They are a useful guide, not a promise, because each new paper is judged on its own demand.
How Wisely Tutors Supports O Level Students
When past papers show a student is regularly a few marks short of the next grade, one-to-one support can focus on those exact gaps instead of reteaching whole topics. Through our O and A Level tutoring service, Wisely Tutors matches students with subject specialists for Cambridge O Level, IGCSE and A Level, including Mathematics, Physics, Chemistry, Biology, English, Pakistan Studies and Islamiyat.
Families can choose a home tutor in Lahore or live online tutoring for students elsewhere in Pakistan or overseas. You can also book a free demo class to see whether a tutor’s teaching style suits your child before you decide.
Frequently Asked Questions
What is a good grade in O Level?
A* and A are excellent results, and B or C shows a sound understanding of the subject. What counts as “good” also depends on your next step. Colleges and A Level programmes set their own entry requirements, so check the grades your preferred institution asks for in the subjects you plan to continue.
Is an A* in O Level the same as 90%?
Not exactly. An A* starts at a PUM of 90, but PUM is not a raw percentage. The raw mark needed for A* changes by subject and series, and in June 2026 it was below 90% of the marks in several subjects, as the threshold examples above show.
Where can I find O Level grade thresholds?
Cambridge International publishes a grade threshold table for each O Level syllabus after every exam series, on the Cambridge O Level pages of its website. Your school’s exams officer can confirm which combination of papers applies to you, so you read the correct row.
Can I work out my PUM from my raw marks?
You can estimate it if you know your total and the thresholds on either side of it, as in the worked example above. Cambridge does not publish a simple formula, though, and some papers are weighted before thresholds apply. Your statement of results is the only official figure.
Does the PUM appear on my O Level certificate?
No. According to Cambridge, the certificate shows your grade, while the percentage uniform mark appears only on the statement of results. When applying to colleges, keep both documents, since some institutions may ask to see your statement as well as the certificate.
Final Thoughts
The O Level grading system becomes much simpler once you separate three ideas: the grade (A* to E, or U), the thresholds that decide it each series, and the PUM that shows where you sit within it. Use past thresholds to set realistic targets, give extra attention to your weakest paper, and measure progress in marks rather than percentages.
If your child needs steady, structured support in a demanding subject, explore Wisely Tutors’ O and A Level tutoring or book a free demo class to get started.