IB Grade Boundaries Explained: Study Smarter, Score Higher

If you have ever finished an IB exam and immediately searched for the grade boundary, you know why these numbers matter. A few marks can separate a 5 from a 6, or a 6 from a 7. The confusing part is that IB grade boundaries are not fixed percentages that stay the same every year.

They are set for each examination session after assessment evidence has been reviewed. The boundary for a 7 can differ by subject, level and session. For students searching for IB grade boundaries 2026, the key rule is simple: check the exact subject, level, assessment model and session before relying on any table.

This guide explains how IB grade boundaries are calculated, what happens during grade awarding, why boundaries change, what the latest public tables can tell you, and how to use them intelligently.

What Are IB Grade Boundaries?

IB assessments usually contain several components with different marks and weightings. Once the weighted results are combined into a total subject score, ranges of scores are mapped to final grades from 1 to 7. The IB calls those ranges grade boundaries.

“The principal means of setting grade boundaries is by a review of the quality of candidate work against grade descriptors.”

A grade boundary is therefore not simply a percentage chosen in advance. It is part of a standard setting process designed to make each grade represent a comparable level of achievement even when assessments differ between sessions.

If you want the wider picture of raw marks, component weightings, internal assessment and diploma points, read our guide to how IB grades are calculated.

How Are IB Grade Boundaries Calculated?

There is no single formula that takes the global average and automatically creates a boundary. The IB combines statistical evidence with professional judgement. Its current assessment guidance describes a process that reconciles information from senior examiners, statistical comparisons, grade standards and experienced teachers.

Student Work Is Marked First

Examiners mark assessment components using subject markschemes and established standards. Internal assessment is included according to the subject's weighting and moderation process.

This gives the IB actual assessment evidence before final boundaries are awarded.

Statistical Evidence Provides a Reference Point

The IB uses Statistically Recommended Boundaries, or SRBs, as one source of evidence. They estimate where boundaries might sit in order to maintain comparable standards from one year to the next.

But SRBs are recommendations, not final boundaries. The IB notes that they can work less well when candidate numbers are small or when a new curriculum or assessment model is introduced.

This distinction matters. Statistical evidence helps examiners judge whether standards are remaining comparable. It does not simply decide how many students are allowed to receive each grade.

Senior Examiners Review Actual Work

This is the judgemental part of grade awarding. Senior examiners consider candidate responses around possible thresholds and compare the quality of that work with grade descriptors.

The IB states that the boundaries for grades 4, 7 and 3 are determined judgementally, in that order. Remaining boundaries are then determined arithmetically by interpolation. This is far more accurate than saying the IB simply “curves” an exam.

An IB assessment guide also describes the Principal Examiner and senior examiners considering professional judgement, statistical evidence, grade descriptions and teacher feedback submitted through G2 forms when determining boundaries.

Final Boundaries Convert the Weighted Total Into a Grade

Once final boundaries are approved, the weighted subject total is mapped to a grade from 1 to 7.

That is why similar percentages can produce different grades across subjects, levels or examination sessions. The number itself matters, but so does the standard of achievement that number represents in that particular assessment.

Why Do IB Grade Boundaries Change?

Boundary movement is normal. It does not automatically mean that IB grading has suddenly become easier or harder.

Assessment Difficulty Can Change

Two examination papers can test the same syllabus while differing slightly in overall difficulty. If an assessment proves more demanding, fewer raw marks may be required to demonstrate the same underlying standard of achievement.

This is one reason simply comparing percentages between years can be misleading.

Statistical Evidence Changes With Each Session

The IB examines statistical information when evaluating proposed boundaries. That evidence helps test whether standards remain comparable with previous sessions.

It is important not to confuse this with a fixed curve. The aim is not to guarantee that a predetermined percentage of candidates receives a 7, 6 or 5. Statistical evidence is one part of a wider awarding process that also includes examiner judgement.

May and November Are Separate Sessions

The Diploma Programme has May and November assessment cohorts. A boundary used for a May examination should therefore not automatically be applied to a November paper.

When checking historical IB grade boundaries, always confirm the session rather than looking only at the year.

Curriculum Changes Can Break Historical Comparisons

Revised papers, component structures, weightings or assessment models can make older boundary tables poor comparisons.

The IB specifically identifies new curricula and new assessment models as situations where standard statistical recommendations may be less reliable.

This is particularly important when researching newer science specifications or any subject that has recently changed its assessment structure.

HL and SL Must Be Checked Separately

Higher Level and Standard Level courses can have different papers, requirements and grade boundaries.

A table for the correct subject but the wrong level is still the wrong table.

The same principle applies when different assessment versions are involved. Historical data is useful only when you know exactly what it represents.

IB Grade Boundaries 2026: What Is Actually Available?

For the May 2026 session, DP and CP results were released from 6 July 2026. The IB says candidates may receive a detailed subject view showing their scaled total mark, lower grade boundary, upper grade boundary and the number of marks required for a grade increase. Access to this information is at the discretion of the school’s IB coordinator.

That creates an important distinction when students search for official IB grade boundaries 2026.

In practice, there is no single public IB webpage functioning as one universal all subject May 2026 grade boundary table. Exact candidate boundary information is surfaced through IB results channels, while public websites often compile historical tables, school data or community sourced records.

This means a trustworthy grade boundary resource should always tell you which session, subject and level its numbers represent.

Latest Public IB Grade Boundary Reference Table

The following figures are the final grade bands currently displayed on publicly accessible subject boundary pages checked in August 2026.

They should be treated as reference points, not as a universal official May 2026 table. Public trackers provide level and historical filters, so students should always select the exact HL or SL course and examination session relevant to them.

Subject	Grade 4 Starts	Grade 5 Starts	Grade 6 Starts	Grade 7 Starts
Mathematics: Analysis and Approaches	34	48	60	73
Mathematics: Applications and Interpretation	32	44	55	66
Biology	36	49	62	76
Physics	35	45	56	67
Economics	42	54	65	77
Business Management	36	48	61	73
English A: Language and Literature	38	52	65	78

The variation is significant. In the public reference data above, the displayed starting point for a grade 7 ranges from the mid 60s to the high 70s depending on the subject. That alone shows why statements such as “80 percent is a 7 in IB” or “70 percent always equals a 6” are unreliable.

There is another important 2026 warning. If a subject has recently moved to a new assessment model, older grade boundaries may refer to different papers, marks or weightings. Comparing several years of incompatible tables can produce a confident looking prediction that has very little value.

Always compare like with like.

How Should Students Use IB Grade Boundaries?

Grade boundaries are useful for planning, but risky when treated as exact targets.

If a recent grade 7 boundary is 73, aiming for exactly 73 in every practice paper leaves no margin for a difficult question, a marking difference or an off day.

A better approach is:

1. Aim above the recent boundary. Build a safety margin rather than training yourself to reach the minimum possible cutoff.

2. Use weighted totals. A percentage on one examination paper is not necessarily your final subject percentage. Component weightings matter.

3. Compare matching sessions. Prioritise recent data from the same subject, level and assessment model. Use older sessions to understand movement rather than predict an exact number.

The purpose of knowing the boundary is to understand where your performance currently sits. Your revision should still focus on gaining marks through stronger subject knowledge, clearer reasoning, precise responses and better exam technique.

IB Grade Boundaries FAQ

Are IB Grade Boundaries Fixed Every Year?

No. IB grade boundaries can change between examination sessions.

The IB conducts grade award processes using evidence from the current assessment session, statistical information and professional judgement about the quality of candidate work.

Are IB Grade Boundaries a Curve?

Not in the simple sense of forcing a predetermined percentage of students into each grade.

Statistical evidence is considered, but candidate work is also reviewed against grade descriptors using senior examiner judgement. The process is designed to preserve standards rather than enforce a fixed quota of 7s, 6s or 5s.

Does 75 Percent Always Mean a 7 in IB?

No.

There is no universal percentage that guarantees a grade 7 across all IB subjects, levels and examination sessions. A score that falls inside the grade 7 range for one subject could fall inside the grade 6 range for another.

Always use the boundary for your exact course and session.

Are May and November Grade Boundaries the Same?

You should not assume that they are.

May and November are separate DP assessment cohorts. Grade boundaries are determined for the relevant examination session, so historical comparisons should always identify whether the data comes from May or November.

Why Can a Lower Percentage Still Earn the Same IB Grade?

Because raw marks and final grades measure related but different things.

If one examination is harder than another, students may earn fewer raw marks while still demonstrating a comparable standard of understanding. Grade awarding helps determine what range of marks best represents each grade standard for that session.

Where Can I Find My Exact IB Grade Boundary?

Start with your detailed candidate results or speak to your DP or CP coordinator.

The IB says the detailed results view can include your scaled total mark, lower grade boundary, upper grade boundary and the number of additional marks required for a grade increase. Whether candidates can access this detailed view is determined by their school coordinator.

Do Internal Assessments Have Separate Grade Boundaries?

Internal assessments have their own criteria, marks and subject weightings, but an IA percentage should not be treated as though it automatically determines your final IB subject grade.

The relevant components are weighted and combined before the overall subject total is mapped to the final 1 to 7 scale.

Do MYP Students Use the Same Grade Boundaries?

No.

MYP has its own assessment and grading structure, so DP subject boundary tables should not be applied directly to MYP results. If you are interpreting an MYP result, What Is a Good MYP Score should be used alongside a dedicated explanation of MYP grading rather than a DP boundary table.

The Bottom Line

IB grade boundaries make much more sense once you stop thinking of them as permanent percentages.

They are thresholds produced through a standard setting process that combines marked student work, statistical evidence, grade descriptors and experienced examiner judgement.

For IB grade boundaries 2026, verify the exact examination session, subject, level and assessment model before using any table. Historical boundaries are excellent planning tools, but they are not promises about what the next boundary will be.

The smartest goal is not to predict the lowest mark that might earn your target grade. It is to build enough mastery that a small movement in the boundary does not decide your result.