A grade boundary is not the same thing across every examination system. Some boards publish session-specific thresholds after marking. Some determine grade boundaries internally using examiner judgment and statistics. Some convert a composite score into a reporting scale. Singapore national examinations publish grading structures, but students should not assume unofficial fixed percentage cut-offs.
Cambridge International: published grade thresholds
Cambridge publishes grade threshold tables after each examination series. A threshold is the minimum mark needed for a particular grade in a component or syllabus combination. Thresholds can move from one series to another so that a grade represents a comparable standard even when a paper is easier or harder.
For some syllabuses, component marks are weighted before they are combined. The applicable threshold therefore depends on the candidate’s exact component combination. Cambridge publishes March, June and November threshold tables where those series apply.
IB: boundaries from marks to grades 1–7
IB combines weighted component marks into total scores, then divides those scores into grades 1–7. IB states that grade-boundary decisions use senior-examiner judgment, candidate work against grade descriptors and statistical evidence. Boundaries can therefore change between sessions.
AP: composite scores converted to 1–5
AP combines section scores into a composite score and then converts that composite to the 1–5 reporting scale. College Board states that AP cut points are based on research that connects AP performance with performance in comparable college courses. A score of 3, 4 or 5 is not produced by one universal percentage rule across all AP subjects.
Singapore national examinations
SEAB publishes the grading systems used for national examinations—for example G3/legacy O-Level grades A1 through 9, and A-Level grades A through U—but a student should not assume internet tables claiming a permanent raw-mark cut-off such as “75% always equals A1”. SEAB’s public 2026 explanation states which grades are considered passes, not a universal fixed raw-mark conversion table for every subject and year.
From 2027, SEC G1, G2 and G3 retain the grading structures corresponding to the preceding N(T), N(A) and O-Level standards respectively. The new SEC also publishes mappings between levels for progression calculations; those mappings are not the same thing as raw-mark grade boundaries.
Why thresholds move
- Paper difficulty can vary.
- Cohort evidence can vary.
- Assessment models can change.
- Boards aim to maintain standards across different examination sessions.
- Component weightings can affect the final total differently.
How students should use historical boundaries
- Use them to understand approximate historical performance, not to predict your exact future grade.
- Always match the correct syllabus, component combination and exam session.
- Do not lower your revision target to last year’s minimum threshold.
- Train for secure mathematical performance with margin for paper variation.
Official sources checked 26 September 2026: Cambridge International grade-threshold guidance, IB assessment guidance, College Board AP scoring information and SEAB national-examination grading information.
World Mathematics route: return to the World Mathematics Atlas for the wider map behind this grading reference: examinations, curricula and current board rules.