How A-Level Grading Works

Behind every A-Level grade is a chain of steps that turns the marks on your scripts into a single letter from A* to E. Understanding that chain makes your results far less mysterious — and helps you target revision where it counts.

Step one: raw marks on each paper

Every component you sit — a written paper, a practical, a coursework portfolio — is marked against a maximum. A paper might be out of 75, another out of 40, a practical out of 30. These are your raw marks. On their own they do not tell you much, because each paper is worth a different share of the qualification and each was set at a slightly different level of difficulty. A raw 60/75 on a hard paper is not the same achievement as 60/75 on an easy one, which is exactly why grading does not stop at raw marks.

Step two: weighting components into a total

A full Cambridge International A Level is built from several components, and each carries a fixed weighting — the percentage of the overall qualification it represents. Your raw marks are scaled to those weightings and added together to give an overall total. A common way this is handled is a uniform mark scale, where each component is converted onto a common footing before being combined, so that a strong paper can genuinely offset a weaker one in proportion to how much each matters.

The practical upshot: a paper worth 40% of the grade moves your final total roughly twice as much as one worth 20%. If you are deciding where to spend your last fortnight of revision, the higher-weighted components deserve the larger share of your attention.

Step three: grade thresholds

Once totals are calculated, examiners set grade thresholds — the minimum total needed for each grade. There is one boundary for A*, one for A, one for B, and so on down to E. Score at or above the A boundary but below the A* boundary, and you are awarded an A. These thresholds are decided after marking, not before, which is the single most important thing to grasp about the system. If a paper turned out harder than intended, boundaries are lowered so that a genuinely A-standard performance still earns an A. That is how Cambridge keeps a grade meaning the same thing year after year, even when paper difficulty drifts. Our grade boundary tables show published thresholds by subject and session.

How AS and A2 combine

A Cambridge International A Level is delivered in two halves. The first half is AS Level, which can be cashed in as a standalone qualification or carried forward. The second half is A2. Together, AS + A2 make the full A Level. Broadly speaking the AS components contribute half of the marks and the A2 components the other half. A student who sat AS in one year can carry that result forward and add the A2 components later; the two sets of marks are then combined and the full A Level grade is awarded from the total.

How the A* is awarded

The A* deserves special mention because it is not simply "the A boundary plus a bit more". At A Level, the A* typically requires both a strong overall total and a high standard in the A2 (second-year) components specifically. In other words, you cannot bank a comfortable AS result and coast to an A* — the top grade is designed to reward sustained performance in the harder, later material. Two students can finish on the same overall total, and the one who scored more of that total in the A2 papers can be the one who lands the A*.

What "U" means

Below the E threshold, no grade is awarded: the result is recorded as U, for ungraded. E is the minimum pass at A Level; there is no D–below or "fail letter" beyond U. A U simply means the total fell short of the lowest graded boundary, and it can usually be improved by resitting.

A worked example

Suppose a subject has four components with these weightings and imagine a student's scaled contribution out of each component's share of a 200-mark overall scale:

If, in this session, the A boundary sits at 160/200 and the A* boundary at 180/200, this student's 170 lands comfortably in the A band. Notice that they are 10 marks short of the A* total — and even if they had scraped to 180 overall, the A2 papers (52/60 and 33/40) would also be checked to confirm the top grade was genuinely earned in the second-year work. To turn this A into an A*, the clearest route is lifting those A2 papers, which are both higher-weighted and directly scrutinised for the A*.

Remember these figures are illustrative — real thresholds change every session. To try your own numbers against the same logic, use the A-Level grade calculator, and see what percentage an A* really takes for the finer detail on the top grade.

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