A-Level Bell Curve Singapore - H2 Grading, Distinction Rates & What Marks You Need (2026)
Study guide
Q: How does the A-Level bell curve work in Singapore?
A: Technically, there is no "bell curve" - MOE and SEAB use criterion-referenced grading with statistical moderation. In practice, grade boundaries shift each year based on paper difficulty and cohort performance, which is why students and parents experience it as a bell curve. This guide covers what we know about grade boundaries, estimated distinction rates, and how moderation works.
TL;DR
MOE officially states that A-Level grades are criterion-referenced (not curved), but statistical moderation is applied to ensure year-on-year comparability. In practice, the raw mark needed for an A grade varies each year. Estimated A-grade cut-offs from school reports and tuition data: H2 Maths 70 - 78, H2 Chemistry 72 - 78, H2 Physics 70 - 76, H2 Biology 72 - 78 (out of 100). These are estimates, not official figures - SEAB does not publish grade boundaries.
Quick reading map
| If you want to know... | Start here |
| Whether there is a real bell curve | What MOE and SEAB actually say |
| What marks might be needed | Estimated grade boundaries |
| How to treat prelim results | Why your school prelim grade is not your A-Level grade |
| What to do with the information | Does the bell curve help or hurt you? |
Concrete example: using an estimated boundary
If an estimated A range is 70 to 78, do not aim for exactly 70. Treat 70 as a danger zone and 80+ as a safer revision target, because the actual boundary depends on paper difficulty and cohort performance.
What MOE and SEAB actually say
SEAB's official position is that A-Level grades are criterion-referenced: each grade (A, B, C, D, E, S, U) represents a defined standard of achievement, not a percentile rank. In theory, if every student achieves the required standard, every student could receive an A.
Reviewed by
Marcus Pang·Managing Director (Maths)
