IB Grading Scale Explained: How Are IB Students Assessed?

You open your IB report and see a 6 next to Biology. Is that 60%? An A? Strong enough for the colleges on your list? Until someone explains the IB grading scale, that one number raises more questions than it answers.

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Every IB subject, at Higher Level and Standard Level, is graded from 1 to 7, with 7 the highest. Your six subject grades add up to 42 points, and Theory of Knowledge and the Extended Essay add up to three more, for a maximum of 45.

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In this guide, we’ll discuss how your work is marked, how grade boundaries turn marks into grades, what counts as a good score, and how US colleges read your results.

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Let’s start with what each number on the scale means.

Key takeaways

• Every IB subject is graded from 1 to 7, with 7 the highest. Since grades reflect published criteria, not a curve, any student can earn a 7.
• External assessment, mainly exams, makes up 70–80% of most subject grades. The remaining share comes from internal assessments (IAs), which teachers mark and IB moderators check.
• After each session, examiners set grade boundaries that turn your weighted mark into a 1–7 grade. Because boundaries move, the same mark can earn different grades across sessions.
• Six subject grades give up to 42 points, and Theory of Knowledge and the Extended Essay add three. Passing, however, takes 24 points plus other minimums.
• In May 2026, candidates averaged 30.88 points out of 45, and 82.61% earned the diploma, according to provisional IB figures. Against that benchmark, anything from 38 upward counts as strong.
• US colleges rely on predicted grades, since results arrive in July. An IB 7 roughly equals an AP 5, and many colleges credit Higher Level grades of 5 to 7.

How the IB grading scale works

In a nutshell, Higher Level (HL) and Standard Level (SL) subjects are both graded from 1 to 7, with 7 the highest.

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In the sections below, we’ll break down what each grade means and why IB grades aren’t curved.

What each IB grade means

Each grade on the 1–7 scale carries an official IB descriptor, from excellent performance at 7 down to very poor performance at 1.

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Here’s what each grade on the scale officially stands for.

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Criterion-referenced, not curved

Criterion-referenced means your work is measured against published quality descriptions, not ranked against other students. For example, each History Paper 2 essay is scored out of 15 against quality markbands.

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Because markbands judge quality, not rank, no fixed share of 7s exists, so in theory every student could earn one. Your own work sets your grade.

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That said, cohort performance still shapes grade boundaries, the minimum marks per grade. Examiners set them each session. If a paper proves unusually hard, the 7 boundary might fall from, say, 78% to 72%.

How IB students are assessed

Your grade in each subject blends external assessment, marked by IB examiners, with internal assessment, marked by your teacher.
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Below, we’ll look at how each one works and how much it counts.

External assessment: exams and externally marked work

Work marked by IB examiners outside your school, not your teacher, is called external assessment. It mainly covers your final written exams, usually Paper 1 and Paper 2, sat in May or November.
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Some HL courses, like Mathematics: Analysis and Approaches, add a Paper 3. Certain coursework counts as well, such as the 1,200–1,500-word HL essay in Language A: Literature. Most subjects weigh these components at 70–80% of your final grade.

Internal assessment and moderation

While IB examiners mark external assessments, your teacher marks course-based tasks called internal assessments (IAs) against IB criteria. In Physics, it’s a scientific investigation of up to 3,000 words, and Economics uses three 800-word commentaries.
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IAs usually carry 20–30% of your subject grade. An IB moderator then re-marks a sample of your class’s work to test the marking. If your teacher marked too generously or harshly, the whole group’s marks move, including work that wasn’t sampled.

From raw marks to final grades: how grade boundaries work

Each exam paper and IA is marked separately, then weighted and combined into one subject mark out of 100. That mark is compared with the session’s grade boundaries, which turn it into your 1–7 grade.
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Take an illustrative subject weighted 40% for Paper 1, 40% for Paper 2, and 20% for the IA. Scoring 75%, 70%, and 80% on those gives 30 + 28 + 16, or 74 out of 100. If that session’s 7 boundary sits at 72, you earn a 7. If it sits at 76, the same 74 becomes a 6.
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Senior examiners set boundaries after marking ends, weighing script quality, statistics, and past sessions. That’s why identical marks can earn different grades across sessions and subjects.

How your IB diploma score is calculated

Once your six subjects each have a 1–7 grade, those grades are added together with up to three bonus points.
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In the sections below, we’ll explain where those points come from and what you need to pass.

Subject grades and bonus points

Your six subject grades can total 42 points, with up to three more coming from two core components.
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Here’s how each part adds to your total.

• Six subjects, each graded up to 7, give a maximum of 42 points (6 × 7). HL and SL grades count equally toward this total.
• Theory of Knowledge (TOK) and Extended Essay (EE) grades, each A to E, combine for up to three points. Our guides to Theory of Knowledge and the IB Extended Essay explain how each is marked.
• Creativity, activity, service (CAS) adds no points, but you must complete it to receive the diploma.
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Here’s how TOK and EE grades combine, which shows why a B in one doesn’t guarantee two points.

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What you need to pass

Reaching 24 points isn’t enough, because the IB also sets minimums for each subject, level, and core component.

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Here’s what you need to earn the diploma.

• At least 24 total points across your subjects and core.
• A grade in every subject, plus TOK and the EE, with no N recorded.
• No grade of 1 in any subject, since even a single 1 blocks the diploma.
• Two grade 2s at most, whether at HL or SL.
• Three or fewer grades of 3 or below across all six subjects.
• HL subjects totaling 12 points or more, counting your three highest if you take four.
• SL subjects totaling at least 9 points, or 5 if you take only two.
• TOK and EE grades of D or above, since an E in either is a failing condition.
• CAS requirements completed and confirmed by your school.
• Zero findings of academic misconduct, such as plagiarism or collusion. 

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Missing any one of these means you won’t receive the diploma, but your effort isn’t lost. You’ll still get a grade for each subject you completed, which colleges can review and may even award credit for. 

Predicted grades, results day, and re-marks

May exam results don’t arrive until July, after most US colleges have made admission decisions. Instead, they rely on predicted grades, your teachers’ estimate of your final grades. Teachers have no fixed formula, so they judge from evidence like mock exams, IA drafts, and classwork.

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Your final grades still matter, though, since colleges may request them to confirm your place or award credit. If a final grade looks wrong, your IB coordinator can request a re-mark, which may raise or lower it. Retaking the subject later is another route.

What is a good IB score?

A good IB score depends on your goals, but the global average gives you a benchmark. In May 2026, candidates averaged 30.88 points out of 45, and 82.61% earned the diploma, according to provisional IB figures. 

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Scoring 24 makes the diploma possible, while scores in the low-to-mid 30s sit comfortably above average. Scores of 38 or more are strong, and 40-plus is rarer, reached by just 11.9% of May 2025 candidates.

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Perfect 45s are rarer still, though the IB stopped publishing how many students reach one in 2023.

IB grades in US college admissions

Colleges see your IB grades in three places: predicted grades, your transcript, and final results, each with a different use.

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In the sections below, we’ll cover GPA conversion, AP comparisons, SAT/ACT scores, and college credit.

Converting IB grades to GPA

There’s no official way to convert IB grades to a GPA. The IB doesn’t endorse any conversion table, because US grading scales are set locally by states and school districts.

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Your GPA comes from your school’s class grades, not your IB exam results. Many colleges then recalculate it using their own criteria, so focus on strong class grades rather than conversion charts.

How IB grades compare with AP scores

AP scores run from 1 to 5, usually from a single May exam. IB grades, by contrast, range from 1 to 7 across several components. No official conversion exists, so each college sets its own credit and placement policies. 

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Here’s an illustrative look at how IB grades roughly line up with AP scores. 

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IB grades, SAT/ACT, and elite colleges

At test-required colleges, your IB results sit alongside SAT or ACT scores rather than replacing them. Harvard, MIT, Stanford, and Yale all require one for the 2026–27 cycle. Yale’s earlier policy let IB scores substitute, but it ended this cycle.

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Elite colleges don’t publish IB cutoffs. They read your grades for rigor in context, so strong predicted grades in major-related HL subjects matter most. A future pre-med student, for example, gains most from 6s and 7s in Biology HL and Chemistry HL.

Which IB grades earn college credit

Many colleges award credit for HL grades of 5, 6, or 7, often placing you out of an introductory course. SL credit is less common, and some colleges grant none.

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Some also give extra credit or advanced standing to full diploma holders. Keep in mind that policies change yearly, so check each college’s IB credit chart after admission.

Build skills that lift your IB grades with Immerse Education

Your IA and Extended Essay reward skills like framing research questions, which classes rarely teach directly. So students often first practice them when marks already count.

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With Immerse Education, you can build those skills earlier. Our Pre-University Summer School offers university-style study in 20+ subjects for ages 13–18, ending with a personal project you present.

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If you’re 15–18 and curious where a subject leads, our Career Insights summer school shows you. Working professionals teach theory, then off-campus industry visits, like a courtroom or trading floor, show it in action. And our Online Research pathway lets you write a research paper remotely, guided 1:1 by an Oxford, Cambridge, or Ivy League tutor. 

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No matter the pathway, you’ll experience your subject firsthand, then return to IB with skills your IA and EE reward.

FAQs

Is IB graded on a curve?

No, IB grades aren’t curved. Examiners mark your work against published criteria, so every student could earn a 7. Grade boundaries can shift each session, but there’s no fixed quota for any grade.

Do colleges see predicted IB grades?

Yes, colleges see your predicted IB grades during applications. Because May results arrive in July, after most US admission decisions, your teachers’ predictions carry much of the weight alongside your transcript.

Can you retake IB exams?

You can retake IB exams in a later session. Speak to your IB coordinator first, since retake options and timing depend on your school, and a re-mark may sometimes be the better route.

Is 38 out of 42 a good IB score?

Yes, 38 out of 42 is a strong result. It means averaging above 6 across your six subjects, and up to three core points could lift your total to 41 out of 45.

How do IB grades convert to GPA?

There’s no official way to convert IB grades to GPA. Your GPA comes from your school’s class grades, and many colleges recalculate it using their own criteria rather than any conversion chart.

What is a 7 in IB equivalent to?

A 7 in IB is the top grade and roughly equivalent to an AP 5. For credit, many colleges treat HL grades of 6 or 7 like AP scores of 4 or 5.

Conclusion: making sense of your IB grades

Every IB grade you receive follows the same path. Your work is marked against published criteria, checked through moderation, and turned into a 1–7 grade using that session’s boundaries.

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Those grades then build a diploma score out of 45, which colleges read alongside your transcript. Once you see how IB grading turns marks into points on the scale, you know where to focus.

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Your IA and Extended Essay are completed before exam day, so they reward early, steady work. For subject-specific advice on papers, IAs, and more, explore our IB preparation resources.

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And if you want to build those research and writing skills before your IA and EE begin, discover how Immerse Education can help you take the next step.