This guide covers what PUM is, how Cambridge calculates it, how it differs from raw marks and past-paper scores, and how to use it to decide between a review of marking, a resit or moving on.
Quick answer
- PUM is a 0–100 score that places you within your grade band. It is not a second grade.
- Each grade maps to a fixed PUM range. An A is always 80–89 and a B is always 70–79, in every series.
- High in the band means a secure grade; low in the band means you only just made it.
- PUM is not your percentage of raw marks. It is calculated from where your raw total falls between that series' grade thresholds.
PUM stands for percentage uniform mark. Cambridge shows it on statements of results for Cambridge IGCSE, O Level and International AS & A Level in the countries where it is reported. It never appears on your certificate.
PUM ranges by grade
| Grade | PUM range |
|---|---|
| A* | 90–100 |
| A | 80–89 |
| B | 70–79 |
| C | 60–69 |
| D | 50–59 |
| E | 40–49 |
| F (IGCSE only) | 30–39 |
| G (IGCSE only) | 20–29 |
These ranges come from Cambridge's guide to percentage uniform marks. Cambridge International AS Level has no a* grade, so an AS a covers 80–100. No PUM is given when a result is Ungraded, No Result, Pending or To Be Issued.
Key point
A B (79) and a B (70) look identical on a certificate, but one student was a mark or two from an A and the other was a mark or two from a C. PUM tells you which you were.
Raw mark vs grade threshold vs grade vs PUM
| Term | What it is | When you know it |
|---|---|---|
| Raw mark | The marks you actually scored on your papers | After marking (you rarely see it directly) |
| Grade threshold | The minimum raw mark needed for each grade in that series | Published on results day |
| Grade | A*, A, B and so on | Results day |
| PUM | Your position within the grade, on a 0–100 scale | Results day, on your statement of results |
How PUM is calculated (worked example)
Cambridge converts your total mark for the whole syllabus into PUM. Each grade threshold is pinned to the bottom of its PUM band, and marks in between are spread evenly. Cambridge's own example: a student exactly halfway between the grade D and grade C thresholds gets a PUM of 55.
Worked example
A syllabus marked out of 200. This series:
- B threshold = 120 raw marks → PUM 70
- A threshold = 140 raw marks → PUM 80
The B band covers 20 raw marks and 10 PUM points, so each PUM point is worth 2 raw marks.
| Student | Raw total | Working | PUM | Grade |
|---|---|---|---|---|
| Aisha | 120 | 70 + (0 ÷ 20 × 10) | 70 | B |
| Ben | 130 | 70 + (10 ÷ 20 × 10) | 75 | B |
| Chen | 138 | 70 + (18 ÷ 20 × 10) | 79 | B |
All three got a B. Chen was 2 raw marks from an A. Aisha had the exact minimum for a B: one mark fewer and she would have had a C.
Two things to take from this:
- Each PUM point covers a different number of raw marks, depending on how far apart that series' thresholds are.
- Thresholds move every series, so the same raw score can produce a different PUM, or even a different grade, in different years.
Your turn
In June 2026, one Cambridge IGCSE Biology 0610 Extended route (Papers 21, 41 and 61) had a B threshold of 110 and an A threshold of 138, out of 200. What PUM would a raw total of 124 give?
AnswerShow answerHide answer
The B band covers 138 − 110 = 28 raw marks for 10 PUM points. 124 is 14 marks above the B threshold, exactly halfway, so PUM = 70 + (14 ÷ 28 × 10) = 75, a mid B.
You can find the real thresholds for that series on Starley's Cambridge 0610 boundaries page, and for every other Cambridge syllabus on our grade boundaries hub.
PUM is not your past-paper percentage
Scoring 78% on a 2023 paper at home does not mean you will get a PUM of 78 on results day. Three things cause the gap:
| Reason | What happens |
|---|---|
| Thresholds differ | 78% of the raw marks could be an A one year and a B the next |
| Self-marking is generous | Students tend to over-award method marks and essay levels, especially when tired |
| Components are weighted | Your syllabus total is not a simple average of paper percentages |
Tip
A better approach is to convert your past-paper raw total using that year's grade thresholds, then work out a PUM from them. Get essays marked strictly against the mark scheme, ideally by a teacher. Starley's past papers are organised by board and code.
What to do with your PUM after results day
These are practical suggestions, not official Cambridge rules.
| Your result | What it means | Suggested next step |
|---|---|---|
| Grade met, high in the band (e.g. 75–79 or 85–89) | A secure grade | Move on; no resit needed |
| Grade met, low in the band (e.g. 70–72 or 80–82) | You only just made it | Fix weak areas before the next stage (A Level or university) |
| One grade short, top of the band (e.g. 78–79 or 88–89) | Very close to the next grade | Ask your school whether an enquiry about results is worth it, then consider a resit |
| Target missed, low or mid-band | A real skills gap | Resit with a new revision plan; a review is unlikely to bridge it |
Important
Cambridge's enquiries about results process can lower your mark and grade as well as raise them, and only your school or exam centre can submit one. A small difference that falls within marking tolerance leaves the original mark unchanged. Weigh the risk before applying, especially if you already have the grade you need.
For resit timing and planning, see our IGCSE resit dates 2027 guide.
Cambridge PUM vs Edexcel UMS: do not mix the numbers
Pearson Edexcel uses the Uniform Mark Scale (UMS) for modular qualifications, including International A Level units and modular International GCSEs, where unit results are converted and then cashed in for an overall grade.
Cambridge says its PUM uses the same approach as UMS. The difference is the scale: PUM is always out of 100, while UMS totals vary by qualification (a modular IGCSE might be out of 200 or 240, for example). So the numbers are not directly comparable. If your school uses both boards, compare Cambridge PUMs only with Cambridge PUMs. For how UMS works, see Edexcel IGCSE modular vs linear.
How to raise your PUM on a resit
Your PUM only rises when your raw total rises. The fastest raw-mark gains usually come from:
- Precise definitions. Key-term marks are the easiest to lose and the easiest to win back.
- Finishing every paper. A blank answer scores zero; a partial answer often picks up method or level marks.
- Reading command words. "Explain", "assess" and "evaluate" are marked differently, so answering the wrong one caps your marks.
- Weekly timed past papers, marked strictly. Track your raw total against real thresholds, not just your percentage.
For a step-by-step plan, see how to start revision. For how Cambridge compares with other boards, see Cambridge vs Edexcel vs OxfordAQA IGCSE.
Frequently asked questions
What does the number in brackets on my Cambridge results mean?
It is your percentage uniform mark (PUM), a 0–100 score showing where you sit within your grade. For example, B (74) means a mid-to-high B.
Is PUM the same as my percentage?
No. PUM is scaled using that series' grade thresholds. A PUM of 80 means you reached the A threshold exactly; it does not mean you scored 80% of the marks.
Does PUM affect my grade?
No. Your grade comes from your raw total and the grade thresholds. PUM simply gives you more information about where you sit within that grade.
Does Cambridge publish grade thresholds in advance?
No. Thresholds are published after each series. Past thresholds are useful for practice, but they do not predict the next series.
Do universities see my PUM?
PUM appears on your statement of results, not on your certificate. Most application systems ask for grades only, though some universities or scholarships ask for full statements, so check each application's requirements.
Is PUM shown for IGCSE and O Level?
Yes, where PUMs are reported in your country, Cambridge statements for IGCSE, O Level and International AS & A Level include them alongside the grade. Check the key on your own statement.
How many raw marks is one PUM point?
It depends on the gap between that series' thresholds. If the B and A thresholds are 20 raw marks apart, each PUM point in the B band is worth 2 raw marks; if they are 28 apart, each point is worth 2.8 raw marks.
Can my PUM change after an enquiry about results?
Yes. After an enquiry about results, your PUM can go up, go down or stay the same, and so can your grade.