IB Grades & Scoring: How the IB Grading System Actually Works

IB Grades & Scoring:

The IB grading system confuses almost every student the first time they see it, a 45-point scale, subject grades that shift every session, and a mysterious set of "grade boundaries" nobody explains clearly. But once you understand how the points actually add up, predicting and improving your score stops being guesswork.

This guide breaks down exactly how IB grades are calculated, what grade boundaries really mean, how to convert your score to a percentage or GPA, and how Baccalytics mock exams help you track your predicted grade before results day.

Check Your Predicted Grade with a Free Mock Exam →

Table of Contents:

• How IB Grades Are Calculated
• The 1–7 Points Scale Explained
• IB Grade Boundaries: What They Are and Why They Change
• Converting IB Grades to Percentage & GPA
• Predicted Grades vs. Final Grades
• IB Grade Boundaries by Subject
• FAQs

How IB Grades Are Calculated:

Every DP student takes six subjects, each graded on a 1–7 scale, for a maximum of 42 points. On top of that, the Theory of Knowledge (TOK) course and the Extended Essay (EE) can add up to 3 additional points based on a combined performance matrix bringing the total possible score to 45 points.

Each subject grade is itself a combination of two components:

• Internal Assessment (IA): coursework marked by your teacher and moderated by the IB, typically worth 20–30% of the subject grade.
• External Assessment: the final written exams, marked by IB examiners, typically worth 70–80% of the subject grade.

These raw marks are added together into a total mark out of a fixed maximum for that subject then converted into a 1 to 7 grade using that session's grade boundaries.

The 1 to 7 Points Scale Explained:

Each subject grade reflects a general standard of performance, not just a percentage cutoff. Here's what each grade signals:

IB Grade Boundaries: What They Are and Why They Change:

Grade boundaries are the raw mark ranges that convert a total score into a 1 to 7 grade for a specific subject, in a specific exam session. They are not fixed percentages, a 65% in one subject one year might be a 6, and a 5 the next, because boundaries are set after the exams are sat, based on how the overall cohort performed and the difficulty of that particular paper.

This is why memorizing "70% = grade 6" from an old paper is unreliable. The only accurate way to check where you stand is against boundaries from the same subject and the same session, which is exactly what our grade boundaries breakdown covers in detail.

Read: IB Grade Boundaries 2026 →

Converting IB Grades to Percentage & GPA:

Universities and schools outside the IB system often need an approximate percentage or GPA equivalent. These conversions are rough guides, not official IB conversions, since exact ranges shift by subject and session:

Predicted Grades vs. Final Grades:

Predicted grades are your teachers' professional estimate of your final subject grades submitted to universities well before your actual exams, they're what most conditional university offers are based on. They're built from your coursework, mock exam performance, and classroom assessment throughout the DP.

Final grades are calculated after your real exams and IA are marked and moderated by the IB. The two can differ sometimes significantly, which is exactly why sitting realistic mock exams under real conditions matters: a mock exam score grounded in actual exam-style performance gives both you and your teachers a far more accurate predicted grade than classwork alone.

IB Grade Boundaries by Subject:

Boundaries vary meaningfully by subject. Explore how scoring works for the subjects Baccalytics covers:

• IB Mathematics AA & AI Grade Boundaries
• IB Physics Grade Boundaries
• IB Chemistry Grade Boundaries
• IB Biology Grade Boundaries
• IB Economics Grade Boundaries
• IB English A Grade Boundaries
• IB Business Management Grade Boundaries
• See all subjects →

FAQs:

What's the highest possible IB score?

45 to 42 points from six subject grades 7 points each plus up to 3 bonus points from the combined TOK and Extended Essay grade.

What's a good IB score?

There's no single answer since it depends on your target universities, but 30+ points is generally considered strong, and 38 to 40+ is competitive for highly selective programs.

Do grade boundaries change every exam session?

Yes. Boundaries are recalculated each session based on cohort performance and paper difficulty, so the same raw mark can convert to a different grade from one session to the next.

How are predicted grades used by universities?

Most universities make conditional offers based on predicted grades before final results are released, then confirm the place once your actual final grades are published.

What happens if I score below 24 points?

24 is generally the minimum threshold to be awarded the full IB Diploma, alongside other conditions such as no grade below 2, and limited grade 3s. Falling short usually means receiving individual subject certificates instead of the full Diploma, check your school's specific requirements, as some conditions vary.