How IGCSE grading works

Every IGCSE grade starts life as a raw mark on a paper — but the number you see on results day has been through several steps first. Understanding those steps takes a lot of the mystery (and stress) out of results season, and it helps you revise with a clear target in mind. Here's the whole journey, from the marks you earn to the grade that lands on your certificate.

From raw marks to a grade, step by step

Grading isn't a fixed percentage rule. It follows a sequence:

1. You earn raw marks on each paper (also called a component).
2. Your marks are added up across all the papers for that subject, using each paper's weighting.
3. Grade boundaries are set for that specific subject and exam session — the minimum total mark needed for each grade.
4. Your total is compared to those boundaries, and you're awarded the grade you've reached.

The important idea is that boundaries are decided after the exams are marked, not before. That's why nobody can tell you in advance the exact percentage you'll need — it's confirmed at the end of each session.

The two grading scales: 9–1 and A*–G

Most IGCSE subjects now use a numerical 9–1 scale, where 9 is the highest grade and 1 is the lowest pass grade. This is used by Cambridge (CAIE) and Pearson Edexcel for the majority of their International GCSE subjects. In the UK-aligned wording, a grade 4 is often called a "standard pass" and a 5 a "strong pass", while a 7 is broadly equivalent to the old grade A.

The older A*–G scale (with A* at the top) is the legacy system and still appears on some subjects and in some regions. The two scales don't map perfectly onto each other, but as a rough bridge: a grade 9 sits above the old A*, a 7 lines up roughly with an A, and a 4 sits around the old C. If you're converting between systems, our grade-to-percentage converter shows what each grade means for a given subject.

Core vs Extended (Cambridge tiers)

In many Cambridge subjects — Mathematics, the sciences and others — you sit one of two tiers:

• Core covers the foundation content and caps the top grade you can reach (typically the mid-range of the scale).
• Extended covers additional, harder content and gives access to the very top grades.

The tier decides which papers you sit and therefore which grades are available to you, so choosing the right tier matters. A confident student aiming for a 7, 8 or 9 needs the Extended tier; Core is designed for a solid pass in the middle of the range.

Why every paper doesn't count equally

A subject is usually made of several components, and they're often weighted differently. A subject might combine, say, a multiple-choice paper worth 30% of the total, a written paper worth 50%, and a practical or alternative-to-practical paper worth 20%. So a paper marked out of 40 and a paper marked out of 80 don't necessarily carry the same influence on your grade — the weighting decides that. Always check how your subject's papers are weighted so you know where the marks really are.

Why boundaries move from session to session

Grade boundaries are re-set for every session precisely so that a grade means the same thing regardless of how hard that year's paper was. If a paper turns out to be unusually tough, the boundaries come down a little; if it's more accessible, they go up. The goal is fairness: two students of the same ability should get the same grade whether they sat an easy paper or a hard one.

A worked example

Imagine a subject where the total is 100 marks. In a June session, examiners judge the paper to be demanding, and the grade 9 boundary is set at 79 — so 79% secures a 9. The following June, the paper is a little easier, and the grade 9 boundary rises to 82. Same grade, same standard of achievement, but a different percentage — because the papers weren't equally hard. A student who scored 80% would earn a 9 in the first session but just miss it in the second. This is exactly why treating any single percentage as "the number you need" can mislead you.

What "ungraded" (U) means

If your total falls below the lowest grade boundary, the result is recorded as U, for ungraded. It isn't a grade on the scale — it means the mark didn't reach grade 1 (or grade G on the old scale). A U can usually be re-sat in a later session, and it doesn't appear as a numbered grade on your certificate.

How to use this when you revise

Because boundaries shift, the smart approach is to work with a range rather than a single magic number. Mark your past papers honestly, add them up with the correct weighting, and compare your total to the published boundaries from several recent sessions. If you'd have cleared the grade 9 line in most of them, you're genuinely on track; if you only scrape it in the easiest session, you've found where to push.

To skip the arithmetic, drop your marks into our IGCSE grade calculator. It combines your component scores, applies real boundaries, and shows the grade you'd land — plus how many more marks you'd need to reach the next one.

Independent study tool. Not affiliated with, endorsed by, or connected to Cambridge Assessment International Education or Pearson Edexcel. Grade boundary figures are sourced from official releases; always confirm with your exam board.