The O-Level / SEC G3 grading system has nine grades — A1, A2, B3, B4, C5, C6, D7, E8 and 9 — and the Singapore Examinations and Assessment Board (SEAB) counts A1 to C6 as a subject pass. From 2027 the O-Level becomes the Singapore-Cambridge Secondary Education Certificate (SEC), and G3 subjects keep exactly this scale, while G2 subjects are graded 1 to 6 and G1 subjects A to E. This guide from Ancourage Academy explains what each grade means, what SEAB does and does not publish about marks, and how a grade turns into the points that decide junior college and polytechnic admission. Our tutors prepare Secondary 3 and 4 students for these papers in the secondary tuition programmes at Bishan and Woodlands, so the questions below are the ones parents ask us most often after a results slip or a report book comes home.
The O-Level / SEC Grades A1 to 9, and What Counts as a Pass
A G3 subject is graded on a nine-point scale from A1 (best) to 9 (lowest), and grades A1 to C6 are subject passes. SEAB confirmed the pass line in a written parliamentary reply in May 2026: "Grades A1 to C6 for GCE O-Level and grades A to E for GCE A-Level are considered subject passes." The same reply notes that pass grades are what post-secondary institutions use to decide subject eligibility — for example, a pass in Mathematics for engineering courses.
| Grade | Point value in an aggregate | Subject pass? |
|---|---|---|
| A1 | 1 | Yes |
| A2 | 2 | Yes |
| B3 | 3 | Yes |
| B4 | 4 | Yes |
| C5 | 5 | Yes |
| C6 | 6 | Yes (the lowest pass) |
| D7 | 7 | No |
| E8 | 8 | No |
| 9 | 9 | No (the lowest grade) |
Three points in that table cause the most confusion:
- "F9" is an informal name. SEAB writes the lowest G3 grade simply as "9". Parents, students and many schools still say "F9", and it means the same grade — but you will not see an F on an official SEAB list.
- D7 and E8 are not passes, but they are not nothing. SEAB awards the SEC certificate if a candidate obtains E8 or better in at least one G3 subject, so a student whose best grade is E8 still receives one. Some admission rules also accept a D7 in a specific subject — MOE's JC criteria from the 2028 Post-Secondary Admissions Exercise (PSE) accept A1 to D7 in G3 Mathematics, for instance, while G3 English needs A1 to C6.
- The number in each grade is its point value. An A1 counts as 1 point and a C6 as 6 when grades are added into an aggregate, which is why a lower aggregate is better.
Does SEAB Publish the Mark Range for Each Grade?
No. The SEAB material we cite gives no mark boundaries for any grade, and SEAB has not published a percentage range for A1, B3, C6 or any other grade. The tables that circulate online — "A1 = 75% and above, A2 = 70–74%" and so on — come from tuition websites and forums, not from SEAB, and should be treated as unofficial folklore rather than a rule your child's paper is marked against.
The clearest evidence is the same May 2026 parliamentary question. It asked the Minister for Education for "the passing grades and their corresponding marks banding in the 'O' and 'A' Levels examinations". The written reply gave the nine-point scale and the pass grades, and gave no mark bands at all.
What this means in practice:
- Do not convert a school percentage into a predicted national grade. Schools set their own internal grade cut-offs for class tests and preliminary examinations, and those vary between schools and between years. A "75% = A1" rule on a prelim paper is that school's rule.
- Read the trend, not the label. A student moving from 58% to 68% across three school papers of similar difficulty is improving, whatever letter each paper printed.
- Be sceptical of anyone quoting exact bands with confidence. If a source cannot point to a SEAB document, the band is a guess.
We also do not describe O-Level grading as "bell-curved" or "moderated" to a fixed distribution: SEAB's public pages we cite do not state how grade thresholds are set, so we will not either.
SEC Grading From 2027: G3, G2 and G1
From 2027 the O-Level, N(A)-Level and N(T)-Level are combined into one examination, the SEC, and each subject level keeps the grading scale of the examination it replaces. SEAB's SEC page states that "the G1, G2 and G3 subjects adopt the same grading structure as the N(T)-, N(A)- and O-Level examinations respectively." The first SEC examinations are sat in 2027 by the 2024 Secondary 1 intake, along with Secondary 5 students who entered Secondary 1 in 2023, and results are released in January of the following year, on the same timeline as O-Level results today.
| SEC subject level | Grades | Grade needed for the certificate | Former examination |
|---|---|---|---|
| G3 (O-Level / SEC) | A1, A2, B3, B4, C5, C6, D7, E8, 9 | E8 or better | GCE O-Level |
| G2 (SEC) | 1, 2, 3, 4, 5, 6 | Grade 5 or better | GCE N(A)-Level |
| G1 (SEC) | A, B, C, D, E | Grade D or better | GCE N(T)-Level |
Each candidate receives a single SEC certificate that lists each subject with the level it was taken at. Because Full Subject-Based Banding lets one student take, say, Mathematics at G3 and Chinese at G2, a single certificate can carry grades on two or three different scales. For how subjects are placed at each level and how a subject moves up, see our G2 vs G3 subject levels guide; for everything else that changes in 2027, see the SEC exam 2027 guide.
Two cautions on reading the SEC scales. First, a G2 "1" is not the same achievement as a G3 "A1" — they are the top grades of two different papers set at two different standards. Second, the G1 letters A to E are not the G3 letters: a G1 "A" is the best grade on the G1 paper, not an A1.
How Grades Become L1R5, L1R4 and ELR2B2 Points
Post-secondary admission adds the point values of selected G3 grades into an aggregate, and the lower the total, the stronger the application. Which subjects count, and how many, depends on the route and the year.
Junior college: L1R5 until the 2027 intake, L1R4 from 2028
Students who sat the last O-Levels in 2026 apply through the Joint Admissions Exercise with L1R5: one first language plus five relevant subjects, six grades in all, with a gross aggregate of 20 or less needed for JC. From the 2028 PSE — the first SEC cohort — MOE uses L1R4: a first language plus four relevant subjects, five grades in all. MOE's published JC and MI criteria are:
- L1: G3 English or Higher Mother Tongue Language
- R1: the best-scoring G3 Humanities subject
- R2: the best-scoring G3 Mathematics or Science subject
- R3: the best-scoring G3 Humanities, Mathematics or Science subject
- R4: any best-scoring G3 subject
- Threshold: an L1R4 gross aggregate of 16 or less for JC, 20 or less for Millennia Institute
- Bonus points: up to 3, subtracted from the gross to give the net aggregate, plus 2 more for selection into a JC language elective programme
MOE is explicit that "all subjects used in aggregate score computation for JC and MI admissions must be taken at G3." A worked example: A1 English (1) + B3 History (3) + A2 A-Maths (2) + B4 Chemistry (4) + A2 Chinese (2) = an L1R4 gross of 12. The best possible L1R4 gross is 5. For what the switch means for subject choices, read our L1R4 JC admission guide, and try your own grades in the JC admission calculator.
Polytechnic: ELR2B2
Polytechnic diploma admission uses ELR2B2: English Language, two relevant subjects and two best subjects, minus any CCA bonus points. Under MOE's polytechnic criteria from the 2028 PSE, the ELR2B2 net aggregate must not exceed 22 (for the Diploma in Nursing, an ELR2B2-C net aggregate of 24 or less). EL, R1, R2 and B1 use G3 grades; the second best subject (B2) may be a G2 or G3 subject and is counted on the G2 scale. MOE also states that a G3 grade 9 and a G2 grade 5 or 6 cannot be used in the ELR2B2 computation. You can model a score with our ELR2B2 calculator.
G3-to-G2 Grade Mapping: A Short Summary
When an aggregate needs to combine grades from different levels, SEAB maps the higher-level grade down: A1–B3 becomes G2 grade 1, B4–C6 becomes 2, D7 becomes 3, E8 becomes 4 and 9 becomes 5. A G2 grade maps to G1 in the same way: 1–3 becomes A, 4 becomes B, 5 becomes C and 6 becomes D.
SEAB is careful about scope. Grade mapping "is only used when there is a need to compute aggregate scores using grades of subjects taken at more demanding levels for purposes of post-secondary progression" — for example the ELR2B2 B2 slot, or the ELMAB3 aggregate for the Polytechnic Foundation Programme (PFP) and Year 2 of Higher Nitec. It is not a statement that an A1 and a G2 "1" are equal achievements, and it never runs upwards: a G2 grade is never converted into a G3 grade for JC. The full table, worked examples and what the mapping means for polytechnic and PFP applications are in our G3-to-G2 grade conversion guide.
How Ancourage Academy Prepares Sec 3 and Sec 4 Students
Because the grade boundaries are not published, we prepare students against the syllabus and the marking criteria, not against a percentage target. In small classes of 3–6 students, our tutors work from each subject's SEAB syllabus and assessment objectives, so a student knows exactly which skills earn marks in each paper.
- Grade-sensitive subject planning: under L1R4 each counted subject is one of five, so one weak grade weighs more. We help families see which subjects sit in R1 to R4 and where a single grade move changes the aggregate.
- Error analysis over raw scores: after every school paper we sort lost marks into content gaps, method errors and time management, and work on the largest bucket first.
- Level-matched teaching: for students taking some subjects at G2 and others at G3, lessons follow the paper the student will actually sit.
Classes run at our Bishan and Woodlands centres for Sec 4 E-Maths, A-Maths, English and the Sciences. A trial class (usually $18) includes a short diagnostic, so you leave with a clear view of where your child's marks are being lost.
Frequently Asked Questions
What is a pass in the O-Level / SEC?
A1 to C6 is a pass in an O-Level or SEC G3 subject, as SEAB confirmed in May 2026. D7 and E8 are not passes, but an E8 or better in at least one G3 subject still earns the SEC certificate. The lowest grade, 9, is often called F9.
Is F9 an official O-Level grade?
F9 is the informal name for the lowest G3 grade. SEAB writes it simply as "9" in its grade list for the O-Level and the SEC. The meaning is the same: it is the lowest of the nine grades, below E8, and it is not a pass. A G3 grade 9 also cannot be used in the polytechnic ELR2B2 aggregate.
What percentage do you need for an A1 in the O-Level?
There is no official answer. The SEAB material we cite gives no mark boundaries for A1 or any other grade, and a May 2026 parliamentary reply on grading gave the grade scale and pass grades without mark bands. The "A1 = 75%" tables online are unofficial, and school prelim cut-offs are each school's own.
How is the SEC graded differently from the O-Level?
For G3 subjects it is not graded differently: SEAB states that G3 adopts the O-Level grading structure, so G3 grades still run A1 to 9. What changes is that one SEC certificate also holds G2 grades (1 to 6) and G1 grades (A to E), for subjects taken at those levels.
Does a G2 grade 1 equal an A1?
No. A G2 grade 1 is the top grade on the G2 paper, which is set at the former N(A)-Level standard. SEAB's mapping runs downwards only, turning A1 to B3 into a G2 grade 1 for specified progression aggregates such as ELR2B2 and ELMAB3. JC aggregates from 2028 count G3 subjects only, so a G2 grade cannot fill an L1R4 slot.
How many points is an A1 worth in L1R5 or L1R4?
An A1 is worth 1 point, an A2 2 points, and so on down to 9 points for a grade 9, so a lower aggregate is better. Under L1R4 from the 2028 PSE, five G3 grades are added, the best possible gross is 5, and JC admission needs a gross of 16 or less before bonus points.
Related: SEC Exam 2027 guide · L1R4 JC admission from 2028 · G3-to-G2 grade conversion for poly and PFP · G2 vs G3 subject levels · O-Level / SEC preparation guide