Introduction
Every IB student wonders: “How are IB exams graded?” The answer lies in grade boundaries — the thresholds that determine how raw marks translate into final scores out of 7. Grade boundaries shift from year to year, depending on exam difficulty and candidate performance.
This guide provides insights into IB grade boundaries and result trends, helping you understand what they mean for your revision and how to use them to set realistic goals.
What Are IB Grade Boundaries?
Grade boundaries are the minimum scores needed to achieve each grade (1–7). For example, in one year, a 70% might equal a 6 in Biology HL, while in another year it could be a 7.
They are set after each exam session by considering:
- Exam difficulty: Harder exams result in lower boundaries.
- Statistical analysis: The IB reviews global performance to ensure fairness.
- Consistency: Boundaries are designed to keep standards stable across years.
Why Do Grade Boundaries Change?
- Difficulty variations: Some exams have trickier questions or unusual topics.
- Cohort performance: Boundaries adjust to avoid penalizing or over-rewarding students.
- Paper design: New syllabi or first assessments often have unpredictable boundaries.
For students, this means that your grade doesn’t depend solely on raw percentage — it depends on the boundary set for that year.
Examples of Grade Boundary Shifts
- Sciences: Biology and Chemistry HL often have boundaries that vary by up to 5–10 marks between years.
- Humanities: History essays sometimes lead to higher boundaries because examiners expect more developed answers.
