IB Grade Boundaries Explained: What They Are and How to Use Them
IB grade boundaries are the mark thresholds that turn your raw marks into a grade from 1 to 7. This page explains what they are, why they change between sessions, and how to use them in revision without treating them as a forecast.
Quick definitionA grade boundary is the lowest mark that earns a particular grade.
Your marks from each paper and from the internal assessment are added together, and that combined total is converted into a grade from 1 to 7, where 7 is the highest. The boundaries are the mark thresholds that separate one grade from the next. They are the link between the marks you see on a marked paper and the grade that appears on your record.
The IB sets boundaries for each subject and for each exam session, and it does so after marking is complete. That timing matters. It means nobody can know the exact boundaries while you are still revising. A boundary table is something you read after the fact and use as a rough guide, not a fixed scale you can lean on in advance.
Why IB grade boundaries change
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Paper difficulty
Boundaries are not fixed. They depend on how difficult the papers were in a session, so the marks needed for a 7 or a 5 can differ between sessions and between subjects.
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A comparable standard
A paper that students found harder may lead to a lower threshold for a given grade, while an easier paper may lead to a higher one. The aim is that a grade reflects a comparable standard, even though the raw marks behind it can move.
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A rough guide only
This is why past boundaries are a rough guide only and should never be treated as a promise of next year's cut-offs.
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Where the line has sat
If you see that a grade needed a certain mark last session, that tells you roughly where the line has sat, not where it will sit when your own papers are marked. Think of a past table as a map of the general area, not a precise address.
How IB grade boundaries differ between subjects and papers
Every subject has its own boundariesEach subject has its own boundaries, so one subject's table cannot be compared directly with another's. A grade 6 in one subject does not require the same raw marks as a grade 6 in a different one, because the papers, the mark schemes and the way marks are spread across components are different.
Do not compare tables side by sideLooking at two tables side by side and concluding that one subject is easier or harder is a common but unreliable habit.
Marks come from several componentsWithin a single subject, your marks come from several components, such as separate papers and the internal assessment. They are added together before being converted into a grade, which means a strong paper can offset a weaker one.
Spread your revision sensiblyYou do not need every component to be excellent to reach a grade, but it also means a weak component can pull a total down. Knowing this helps you spread revision sensibly instead of focusing only on your favourite paper.
Common questions about reading IB grade boundary tables
Start with your subject and level
Reading a table is simpler than it first looks. Start by finding the right subject and level. Then find the exam session you want to look at.
Read the lowest mark for each grade
Finally, read the lowest mark that earns each grade. That lowest mark is the boundary: if your total reaches it, you receive that grade, and if it falls below, you receive the grade beneath. Taking these steps in order avoids most of the confusion.
Common mix-ups
Several mix-ups are common. People read a table from the wrong session, compare one subject against another, or treat the lowest mark for a grade as a target to hit exactly.
A threshold is a minimum
A threshold is a minimum, not a goal. Aiming to land precisely on it leaves no room for a difficult question or a lost mark.
Not sure what a column means?
If you are unsure what a column or row means, ask your teacher or a tutor to walk through it with you.
Why you should not predict your final grade from boundaries alone
Mock marks vary with preparation and exam conditionsThe internal assessment is part of your totalReal boundaries are set after marking is completePredicted grades and boundaries are separate ideasMock marks vary with preparation and exam conditionsThe internal assessment is part of your totalReal boundaries are set after marking is completePredicted grades and boundaries are separate ideas
It is tempting to take a mock mark, find a past table and declare your final grade. Boundaries alone cannot tell you that. Mock marks vary with how you prepared and the conditions you sat them in, and your internal assessment is a separate part of the total. On top of that, the boundaries for your real session are set after marking, so the line you are measuring against does not exist yet.
Predicted grades are a separate idea. A predicted grade is a judgement made before the exams, while boundaries are thresholds applied once marking is done. The two should not be mixed up, and neither should be read as a certain forecast of what you will receive. A better use of your time is to treat any estimate as a prompt: where are the marks slipping, and what can you practise this week to improve them?
How to use grade boundaries in revision
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Look at past boundaries
Used sensibly, past boundaries are a helpful planning tool. They can show roughly how many marks a grade usually needs, which helps you set practice targets.
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Set targets with some margin
Because the real boundaries can move, give yourself some margin: aim a little above the mark you think a grade needs, rather than exactly on it. That small cushion makes your plan more resilient if the next session turns out to be less forgiving.
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Review your targets regularly
Review your targets regularly rather than setting them once and forgetting them.
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Compare each practice paper
After each practice paper, compare your mark with your target and decide what to change.
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Guide your effort
The point is to guide your effort, not to calculate a final grade. If a boundary makes you anxious, shift your attention back to what you control: the questions you can practise, the mark scheme you can study and the feedback you can act on.
Finding where you lose marks
The most useful habit is to find the type of question where you lose marks and practise that type. Begin by marking your own past-paper answers against the mark scheme. Be honest and specific: note not only that a mark was lost, but why. Perhaps you missed a key term, left an explanation unfinished, or ran short of time. Patterns usually appear after a few papers, and they tell you far more than a single total does.
A simple routine keeps this manageable. Attempt a paper or a set of questions. Mark it against the mark scheme. Write down the pattern in the marks you lost. Practise that kind of question again, then repeat with fresh material. Over time this turns revision from general rereading into targeted work, and it makes any boundary table far less important, because you are improving the habits that earn marks.
Common mistakes when using grade boundaries
Almost everyone makes some of these mistakes at first, so there is no need to feel bad about them.
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Last year's table as next year's
The first is treating last year's table as next year's. A better habit is to treat it as a rough guide and keep a margin.
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Comparing subjects
The second is comparing subjects. Instead, compare a subject only with its own earlier sessions.
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Fixating on the lowest mark
The third is fixating on the lowest mark for a grade, when a safer approach is to aim comfortably above it.
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Letting a boundary replace feedback
The last common mistake is letting a boundary replace feedback. A number on a table cannot tell you which questions to practise or how to improve an explanation. Your marked papers, mark schemes and teacher comments can. Use boundaries to set a sense of scale, then turn to feedback for the detail. If you are not sure how to interpret your feedback, bring it to a teacher or tutor and ask them to show you how the marks were awarded.
Where tutoring can help
Mark practice papers togetherA tutor can mark practice papers with you, show how marks are awarded and plan revision around your weakest areas.
Understand why a mark was given or missedSitting with someone who can explain why a mark was given or missed often makes a mark scheme easier to understand.
Spot patterns and plan next stepsIt can also help you spot a pattern in your lost marks that is hard to see alone, and turn it into a clear set of next steps.
Share your subjects and levelIf you would like support, tell us your subjects and level and we will help you find a suitable tutor. You can share these details through the consultation form, and our team will be in touch about the next steps.
Tutoring is online, and the aim is simply to help you understand how marks work and use your revision time more clearly, not to forecast a grade.
Frequently asked questions
How do IB grade boundaries work?
Your marks from each paper and from the internal assessment are added together. The total is then converted into a grade from 1 to 7 using the boundaries, which are the mark thresholds for each grade. The IB sets these for each subject and each session after marking is complete.
Why do IB grade boundaries change?
They depend on how difficult the papers were in a session. Because of that, the marks needed for a 7 or a 5 can differ between sessions and between subjects. This is why past boundaries are only a rough guide to what a grade might need.
Are IB grade boundaries the same every year?
No. The IB sets them for each subject and each session, so they can change. A table from an earlier session shows where the thresholds sat then, not where they will sit when your own papers are marked.
What grade is the highest in the IB?
Each subject is graded from 1 to 7, with 7 the highest. Boundaries are the mark thresholds that decide how many marks are needed for each of those grades in a given subject and session.
Can I rely on last year's boundaries?
Treat them as a guide only. Use them to set practice targets, ideally with some margin above the threshold, but do not assume the next session will match them. The real boundaries are set after marking is complete.
How do IB predicted grades relate to grade boundaries?
They are separate ideas. A predicted grade is a judgement made before the exams, while boundaries are thresholds applied after marking. Neither is a certain forecast, so use both as prompts to focus your revision rather than as a final answer.
Talk to us about your IB subjects
Share your subjects and goals through the consultation form and our team will be in touch about the next steps.
