If you are looking for clear information on IB DP Biology grade boundaries, this guide covers the paper structure for both Higher Level (HL) and Standard Level (SL), the way the IB sets boundaries for the 1–7 grade scale, recent threshold patterns, and the most-asked question for any IB Biology candidate: what raw mark do I need for a 7 in IB Biology?

The International Baccalaureate sets official grade boundaries for every subject after each examination session (May or November). Boundaries are visible to schools through the IB Coordinator portal and are referenced in the Subject Reports IB publishes after each session. Below we summarise how IB DP Biology is graded, what boundaries usually look like, and how to use them while you revise.

Free tool: Enter your raw mark in Tutopiya’s IB DP Biology grade boundary tracker (HL) or Biology SL tracker to instantly see the most likely IB grade based on recent-session boundary patterns. Pair it with the IB DP Biology revision checklist to target your revision.

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How IB DP Biology grade boundaries work

A grade boundary is the minimum total raw mark required to be awarded a particular grade. For IB DP Biology, grades range from 1 to 7, with 7 the highest and anything below 1 ungraded.

Three points to remember:

1. Boundaries are set after marking. The IB looks at the difficulty of the actual papers sat and the cohort’s performance, then sets thresholds so that a candidate who performed as well as a comparable candidate from a previous session receives the same grade.
2. Boundaries change every session. A May 2025 grade 7 boundary is not the same as a November 2024 grade 7 boundary. They cluster within a band, but the exact mark moves up or down each session.
3. Boundaries are total marks, not percentages. The IB publishes them as raw marks out of the total available across all assessment components.

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IB DP Biology paper structure (HL and SL)

IB DP Biology is assessed across written papers and the Internal Assessment (IA), with the structure following the syllabus first examined in May 2025.

Higher Level (HL):

Component	Description	Approx. Weight
Paper 1	Multiple choice + data-based questions	36%
Paper 2	Structured and extended-response questions	44%
Internal Assessment	Individual investigation report	20%

Standard Level (SL):

Component	Description	Approx. Weight
Paper 1	Multiple choice + data-based questions	36%
Paper 2	Structured questions	44%
Internal Assessment	Individual investigation report	20%

The IB combines your raw marks across all three components into a total subject mark, which is then mapped to a grade 1–7 using the boundaries set for that session.

For full details and the latest paper-mark allocations, refer to the IB Biology subject brief and your school’s coordinator.

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What raw mark do I need for a 7 in IB DP Biology?

Across recent sessions, the grade 7 boundary for IB DP Biology has typically required somewhere in the 74–84% range of total marks for HL — but the exact figure shifts each session.

Representative bands across recent IB Biology HL sessions:

• Grade 7 has commonly required around 78–82% of total marks.
• Grade 6 has commonly required around 66–72%.
• Grade 5 has commonly required around 54–60%.
• Grade 4 has commonly required around 42–48%.
• Grade 3 has commonly required around 30–36%.

SL boundaries follow a similar percentage pattern but apply to a smaller total mark allocation. Two caveats apply:

1. These bands are typical, not predictions. A particular session might sit a few marks above or below.
2. The IB publishes thresholds as raw marks, not percentages. Always work from the published raw-mark threshold for the specific session you are looking at.

For confirmed boundaries, ask your IB Coordinator for access to the official session boundary table or refer to the Subject Report the IB publishes after each session.

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Why IB DP Biology boundaries move each session

Three factors drive most of the year-to-year variation:

• Paper 2 difficulty. Paper 2 carries the highest weight and includes the most demanding extended-response questions. A particularly challenging Paper 2 — for example, an unusually applied question on photosynthesis or genetics — leads the IB to lower the threshold slightly so candidates are not penalised.
• IA standardisation. Internal Assessment marks are awarded by the school but moderated by the IB. If the moderation reveals a wide spread between centres, this can affect the mark distribution and shift the overall threshold.
• Cohort performance. If the global cohort performs unusually well or poorly, thresholds adjust to maintain comparable outcomes across sessions.

This is why the IB does not publish boundaries before the session — they are set against the cohort’s actual performance.

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How to use IB DP Biology boundaries while you revise

Grade boundaries are most useful before results day. Three practical applications:

1. Convert past-paper marks into a target grade

When you sit a past Paper 2 under timed conditions and score 50/80, that number alone tells you little. Cross-reference with the published boundary for that session — or with the combined-component boundary — and you immediately know whether you are tracking at grade 5, 6 or 7. Add an estimated IA mark to your written-paper total before checking the boundary. The Tutopiya IB Biology grade boundary tracker does this conversion automatically when you enter your combined raw mark.

2. Identify the gap to your next grade

If you are scoring 70% on combined past papers and the historical grade 7 boundary is 78%, you know you need to pick up around eight percentage points to be on the 7 border. Combine the gap with the IB DP Biology revision checklist to choose where those marks come from — typically genetics, ecology, cell biology or the depth of evaluation in extended-response answers.

3. Sanity-check your predicted grade

Schools issue predicted grades for university applications. Predicted grades feed UCAS and most international university applications. If your predicted grade looks higher or lower than the boundary maths suggests, raise it with your teacher early.

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How the Internal Assessment affects your IB Biology grade boundary

The Internal Assessment carries 20% of the final mark and is your single biggest opportunity to bank marks before exams begin. Three implications for boundaries:

• A strong IA (high teens out of 24) lifts your total raw mark before you sit Paper 1 or Paper 2 — you can effectively “carry” marks into the exam.
• A weak IA forces your written papers to do more work, raising the threshold you need to clear on each.
• The IA is moderated, not externally examined — meaning your teacher’s mark may be adjusted up or down by IB moderators. Ask your teacher what mark they have submitted and whether it is conservative or generous against IB criteria.

For IA topic ideas and structuring guidance, see our IB Biology IA topic ideas guide.

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IB Biology grade boundaries: where to find the official numbers

The IB does not publish a single public boundary PDF the way Cambridge does. Four reliable routes to the numbers:

1. Your IB Coordinator’s portal — official boundaries are visible to coordinators after each session.
2. Subject Reports — the IB publishes detailed Subject Reports after each session, including boundary discussion.
3. Your teacher — most experienced IB Biology teachers track session-by-session boundaries.
4. Tutopiya’s IB Biology HL grade boundary tracker and SL tracker — reference patterns from recent May sessions for quick raw-mark conversion.

Treat the tracker figures as a reference band; your IB Coordinator has the definitive numbers.

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Common mistakes students make with IB Biology grade boundaries

• Not including the IA mark. Calculating a boundary based on Paper 1 + Paper 2 alone without adding an IA estimate gives an inflated percentage.
• Mixing HL and SL boundaries. HL and SL have separate thresholds. Confirm which level you are sitting before reading any table.
• Comparing boundaries across subjects. IB Chemistry, Physics and Biology have separate boundaries — the grade 7 for Biology is not the grade 7 for Chemistry.
• Forgetting the boundary is set per-session, not per-year. May and November of the same year have separate thresholds.

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IB DP Biology revision: from threshold to grade

Published boundaries tell you the destination. The route is the same set of evidence-based revision habits:

• Past-paper Paper 2 timing practice. Sit full Paper 2s under timed conditions, marked against the official mark scheme. Use the past paper exam timer to enforce timing.
• Topic-by-topic confidence rating. Use the IB DP Biology revision checklist to mark confidence across every syllabus topic.
• Command-term precision. The IB rewards exact wording — outline, describe, explain, analyse, evaluate — and the depth expected for each command term differs at HL versus SL. Drill the IB command terms.
• IA submission strength. Sit the IA at a true draft state two months before submission so your teacher can give substantive feedback. Late drafts get superficial feedback.

For broader IB Biology preparation, see our IB DP Biology common mistakes guide.

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Frequently asked questions

What are IB DP Biology grade boundaries?

Grade boundaries are the minimum total raw marks required for each grade (1 to 7) in IB DP Biology. The IB publishes thresholds after each session through coordinator portals and Subject Reports.

What raw mark do I need for a 7 in IB Biology HL?

The grade 7 boundary has typically required around 78–82% of total marks across recent sessions, but the exact figure changes every session. Use the Tutopiya IB Biology HL grade boundary tracker to enter your raw mark and see the most likely grade band, or ask your IB Coordinator for the official boundary table.

Are May 2026 IB Biology grade boundaries published yet?

No — the IB publishes grade boundaries on or shortly after results day (typically early July for the May session). Until then, use the most recent published session as a reference band.

Where can I find the official IB DP grade boundaries?

IB grade boundaries are released to schools through the IB Coordinator portal. They are also discussed in the Subject Report the IB publishes after each session. Your IB Coordinator is your most reliable route.

Do HL and SL Biology have separate grade boundaries?

Yes. HL and SL are distinct qualifications with separate paper structures, separate mark totals and separate boundary tables.

Does the Internal Assessment count toward the grade boundary?

Yes — the IA contributes 20% of the final mark in IB Biology. Boundaries are applied to the combined total mark across Paper 1, Paper 2 and the IA.

Why do IB Biology boundaries change every session?

Boundaries are adjusted for paper difficulty and cohort performance so that comparable candidates receive comparable grades across sessions. A harder paper sees the threshold drop slightly; an easier paper sees it rise.

Is the IB grade 7 boundary the same as an A* in Cambridge or Edexcel A Level?

Not exactly. Grade 7 in IB and A* in A Level are broadly comparable in terms of university recognition, but the qualifications use different scales, paper structures and assessment models. Universities consider the IB total points (out of 45) alongside A Level grades.

What happens if I miss the grade 7 boundary by one mark?

The IB does not round up. A candidate one mark below the grade 7 threshold is awarded grade 6. Enquiries upon results can be requested through your IB Coordinator if you believe a paper has been mis-marked.

How does my Biology grade contribute to my total IB points?

Each of your six IB subjects is graded 1–7, contributing up to 42 points. The TOK and Extended Essay matrix adds up to 3 bonus points, for a maximum of 45 points. A grade 7 in HL Biology contributes 7 points to your total.

Does the new (first-exams 2025) IB Biology syllabus have different grade boundaries?

Yes — the new syllabus has a different paper structure (two papers + IA) compared with the legacy three-paper structure. The IB resets boundary expectations for new syllabi based on the first cohorts to sit them.

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Last reviewed: 29 April 2026. IB grade boundaries are released after each session through the IB Coordinator portal and Subject Reports. Always verify current boundaries with your school’s IB Coordinator.

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