How to use a grade boundary
IB assessments can contain several components, each with its own marks and weighting. After the required scaling and weighting, the component marks are aggregated into an overall subject mark. Grade boundaries are the ranges used to convert that overall mark into a final grade from 1 to 7.
The IB says boundaries are determined using multiple forms of evidence, including expert judgement of candidate work against grade descriptors and statistical information. That is why a generic “Grade 7 percentage” cannot accurately describe every subject, level and examination session.
| Match | Why it matters |
|---|---|
| Subject and course | A boundary for one subject, or an earlier course version, does not transfer to another. |
| HL or SL | Use the level shown on the result or assessment information; do not substitute the other level. |
| May or November session | Boundaries belong to a particular examination session and cannot be assumed in advance. |
| Component or overall mark | A paper boundary and the final aggregated subject boundary answer different questions. |
| Authoritative context | Confirm result-specific information with the school DP or CP coordinator rather than an unlabelled table. |
- Match the exact course, level and examination session before interpreting any historical boundary.
- Check whether a number refers to one assessment component or the aggregated overall subject mark.
- Use historical information as context for practice, not as an equation for a predicted or future grade.
- If a mock lands near a boundary, revise for a buffer above it, not for the minimum score.
Common confusions
Assumptions that cost students marks or planning time.
Frequently asked questions
What are IB grade boundaries?
IB grade boundaries are the mark ranges used to convert an aggregated subject score into a final grade from 1 to 7. The IB reviews candidate work against grade descriptors and considers statistical evidence when setting boundaries.
What percentage is needed for a Grade 7 in IB?
There is no single Grade 7 percentage for every IB course. The relevant boundary depends on the exact subject, level, examination session and assessment structure, so a generic percentage or a different session's table should not be treated as the current cutoff.
Are IB grade boundaries the same every examination session?
Not necessarily. The IB reviews boundaries during each grade-award process. Some comparable tasks may retain a boundary, but it can be adjusted when the available evidence shows that a change is needed to maintain comparable grade standards.
How is an IB subject grade calculated?
Marks from the subject's assessment components are combined after the required scaling or weighting. The resulting overall subject mark is then compared with the boundaries for that course and examination session to award a grade from 1 to 7.
Where should I check an exact IB grade boundary?
Ask your school's DP or CP coordinator for the information that applies to your results, and match the exact subject, level and examination session. The public IB assessment pages explain the process, but an unrelated or unofficial table may describe a different course or session.
Sources checked
Every claim on this page is checked against the IB's own publications. Where the two disagree, the IB is right and this page is wrong. Tell us and we will fix it.
Using StudyIB tools?
Read how IB final subject grades are calculated for a worked, hypothetical example of component scaling, weighting and aggregation, then test the gap between your mock mark and the grade you want in the question bank.