What are the great boundaries of IGCSE biology in 2026?
Everything Cambridge students need to know about grade thresholds — and what to expect in June 2026

If you are searching for IGCSE Biology grade boundaries for 2026, you are in the right place. This guide covers every session from June 2023 to November 2025, breaks down the minimum marks needed in each paper, analyses whether June or November is the better sitting, and gives you a data-backed prediction for what the 2026 thresholds are likely to look like. Bookmark this page, share it with your biology teacher, and come back after results day to see how close the prediction lands.
What are grade boundaries in IGCSE Biology?
Cambridge International (CIE) calls them grade threshold tables, but students and teachers commonly call them grade boundaries. They are the minimum total mark a student must score — after all papers are combined and weighted — to be awarded each grade from G up to A*. For IGCSE Biology (syllabus code 0610), the most widely sat combination of papers for extended candidates is Paper 2 (Multiple Choice Extended, 40 marks, 45 minutes), Paper 4 (Theory Extended, 80 marks, 75 minutes), and Paper 6 (Alternative to Practical, 40 marks, 60 minutes). This combination is called Option CY in Cambridge's official threshold tables. The three papers combine for a maximum weighted total of 200 marks, and all grade boundaries in this guide refer to that 200-mark scale unless otherwise stated. One point students must understand from the start: Cambridge does not award A* at the level of individual components. A* only exists at the overall weighted total. There is no such thing as getting A* on Paper 4 in isolation.
IGCSE Biology grade boundaries: June 2023 to November 2025
The overall picture across six sessions
The official grade threshold tables tell a story of remarkable stability. For Option CY across the past three years, the A* boundary has moved within a range of just 13 marks on a 200-mark scale — from a low of 161 in November 2023 to a high of 174 in June 2025. In June 2023 the A* sat at 164, A at 140, B at 116, and C at 93. By November 2023, those figures shifted slightly downward, with A* at 161, A at 138, B at 115, and C holding at 93. June 2024 saw the boundaries climb, reaching 172 for A*, 145 for A, 118 for B, and 91 for C. November 2024 remained high at 172 for A*, 148 for A, 124 for B, and 101 for C — notably the highest C boundary in this dataset. June 2025 pushed further still to 174 for A*, 149 for A, 124 for B, and 99 for C. November 2025 then pulled back, settling at 164 for A*, 139 for A, 114 for B, and 89 for C. Cambridge's awarding process is deliberately calibrated for this kind of stability. Students should not expect dramatic swings from year to year, and they should be equally sceptical of anyone predicting a sudden collapse or a sudden spike in the boundaries for 2026.
Paper-by-paper breakdown: minimum marks per grade
Paper 2 — Multiple Choice Extended (40 marks)
Paper 2 is the shortest paper and the only one where every mark is binary — right or wrong. There are no partial marks, no method marks, and no extended writing. It is also the final paper most students sit in the June series, which makes it uniquely important psychologically and strategically. Across all six sessions from June 2023 to November 2025, the A boundary on Paper 2 has sat between 30 and 33 out of 40. In June 2023 the A boundary was 33, with B at 28 and C at 23. November 2023 dropped slightly to 31 for A, 27 for B, and 23 for C. June 2024 came in at 32 for A, 27 for B, and 22 for C. November 2024 was notably the highest Paper 2 session in this period at 33 for A, 29 for B, and 25 for C. June 2025 settled at 32 for A, 27 for B, and 23 for C. November 2025 was the most accessible sitting with 30 for A, 25 for B, and 21 for C. To perform at grade A level on Paper 2, students need to score between 75% and 82.5% — that is 30 to 33 correct answers out of 40. The threshold has been remarkably consistent, never dropping below 30 or rising above 33 in any of the six sessions covered here. To secure a C on Paper 2, students need roughly 21 to 25 out of 40 — between 52.5% and 62.5%. This is achievable with solid revision of core content alone, making it one of the more forgiving papers for students who are consolidating their knowledge at the last minute.
Paper 4 — Theory Extended (80 marks)
Paper 4 is the most heavily weighted component in the entire combination. At 80 marks it contributes twice as much to the final total as either Paper 2 or Paper 6. This is where grades are made or broken. Structured questions, data analysis, and extended response items test not just knowledge recall but the ability to apply biological understanding in context — explaining mechanisms, interpreting graphs, evaluating experimental design, and constructing arguments using precise scientific language. Across the six sessions, the A boundary on Paper 4 has shown the clearest upward trend of any component. In June 2023 the A boundary was 47 out of 80, with C at 28. November 2023 came in higher at 49 for A and 30 for C. June 2024 reached 50 for A and 28 for C. November 2024 pushed to 52 for A and 32 for C. June 2025 hit the highest boundary in this dataset at 55 for A and 33 for C. November 2025 pulled back to 50 for A and 29 for C — consistent with the general November pattern of slightly lower thresholds. The A boundary has risen by 8 marks in two years from the June 2023 to June 2025 sitting. Students should plan to target at least 50 out of 80 — that is 62.5% — to be competitive at grade A, and should be aiming for 54 to 58 out of 80 if an A* overall is the goal. To secure a C on Paper 4, students need roughly 28 to 33 out of 80, which is as low as 35%. However, scoring at C-level on Paper 4 while aiming for an A* overall is not viable. Paper 4 must be strong.
Paper 6 — Alternative to Practical (40 marks)
Paper 6 replaces the practical examination for students who do not sit Paper 5. It tests experimental design, data interpretation, graph work, and the evaluation of biological investigations. Many students underestimate this paper, treating it as less important than Paper 4 — a costly mistake given it carries the same weighting as Paper 2 and is one of only three components contributing to the final total. The grade thresholds on Paper 6 across the past three years have been extraordinarily stable — arguably the most predictable of all three papers. In June 2023 the A boundary was 32, B at 27, and C at 23. November 2023 dropped slightly to 30 for A, 25 for B, and 21 for C. June 2024 was the highest in this period at 34 for A, 28 for B, and 23 for C. November 2024 sat at 33 for A, 28 for B, and 23 for C. June 2025 came in at 32 for A, 27 for B, and 23 for C. November 2025 offered the most accessible Paper 6 thresholds at 31 for A, 26 for B, and 21 for C. The A boundary on Paper 6 has not left the range of 30 to 34 out of 40 in any of the six sessions. The C boundary has barely moved outside 21 to 23. Students who practise past Paper 6 questions consistently should find this paper highly manageable. The skills it tests — planning experiments, drawing graphs, identifying variables, evaluating methods — are learnable, repeatable, and heavily rewarded by structured revision.
June vs November: which session gives the better chance of an A*?
This is one of the most common questions from students and parents, and the data gives a nuanced answer. Looking at the A* boundary for Option CY, June 2023 sat at 164 — that is 82.0% of the total marks. November 2023 came in at 161, or 80.5%. June 2024 rose to 172, which is 86.0%. November 2024 matched June 2024 exactly at 172, or 86.0%. June 2025 reached the highest point in this dataset at 174, or 87.0%. November 2025 dropped back to 164, or 82.0%. The verdict is that June and November are not always dramatically different, but the June sessions have trended higher for the A* boundary across this three-year window. June 2025 reached 174 out of 200 — the highest recorded in this dataset. November sessions have consistently offered a slightly lower A* threshold, ranging from 161 to 172, compared to 164 to 174 in June. Why does this happen? The June cohort is larger and, on average, includes more students who have completed the full two-year IGCSE programme in a single sitting. November retakers and a smaller overall cohort mean Cambridge calibrates the November thresholds differently. Neither session is objectively easier — the papers themselves vary in difficulty — but historically, November has required fewer total marks to achieve A*. That said, this should not drive a student to choose November over June purely for boundary reasons. The preparation window, the school teaching cycle, and university application timelines are all more important factors in that decision.
What the grade boundaries mean for your revision strategy
Targeting A*
To reach A*, students need approximately 164 to 174 out of 200 depending on the session. Across three papers, that means averaging around 82% to 87% across all components. A working target that achieves this comfortably looks like 33 to 36 out of 40 on Paper 2 — that is 82% to 90% — alongside 52 to 58 out of 80 on Paper 4, which is 65% to 72%, and 32 to 35 out of 40 on Paper 6, which is 80% to 87%. Paper 4 is the biggest leverage point. An extra five marks on Paper 4 is worth more than five extra marks on Paper 2 or Paper 6, because Paper 4 carries double the raw marks. For students preparing for A* on IGCSE Biology, the honest focus of revision should always begin with Paper 4.
Targeting A
Students aiming for grade A need approximately 138 to 149 out of 200. A working target is 30 to 32 out of 40 on Paper 2 — 75% to 80% — combined with 45 to 50 out of 80 on Paper 4 — 56% to 62% — and 30 to 32 out of 40 on Paper 6 — 75% to 80%.
Targeting C (the pass threshold)
Students consolidating for a C need approximately 89 to 101 out of 200. That is achievable with 21 to 23 out of 40 on Paper 2 — 52% to 57% — alongside 28 to 33 out of 80 on Paper 4 — 35% to 41% — and 21 to 23 out of 40 on Paper 6 — 52% to 57%.
Grade boundary prediction for IGCSE Biology June 2026
Based on three years of data across six sessions, here is a data-grounded prediction for June 2026 thresholds on Option CY. The methodology takes the mean of the two most recent June sessions — June 2024 and June 2025 — as the primary anchor, then applies a conservative adjustment to account for the mild upward trend observed on Paper 4. For A* the predicted boundary is 172 to 175, with a broader plausible range of 170 to 178. For A the prediction is 147 to 151, ranging 145 to 154. For B the prediction lands at 122 to 126, ranging 119 to 129. For C the prediction is 97 to 101, ranging 94 to 104. For individual papers, Paper 2 is predicted to carry an A boundary of 32 to 34 and a C boundary of 22 to 24. Paper 4 is predicted to carry an A boundary of 54 to 58 and a C boundary of 31 to 35. Paper 6 is predicted to carry an A boundary of 32 to 34 and a C boundary of 22 to 24. The most important prediction here is for Paper 4. If the upward trend in the Paper 4 A boundary continues — it has risen from 47 in June 2023 to 55 in June 2025 — students should be prepared to score 55 to 58 out of 80 to sit comfortably at grade A level on that paper. This is not a trivial target. It requires genuine command of the extended syllabus content, particularly on topics like genetics, homeostasis, transport in plants and animals, and the coordination and response unit. These predictions are estimates based on historical data. Cambridge sets boundaries after each examination based on that cohort's performance and awarding committee decisions. These figures are for planning and revision guidance only. Always refer to the official Cambridge International grade threshold tables after results are published.
The most important paper you can still influence: Paper 2
For students sitting their final paper — Paper 2 — in the June 2026 series, this is the most actionable section of this entire guide. Paper 2 is 40 multiple choice questions. You cannot lose marks for wrong answers. Every question you get right is a direct addition to your overall total. There is no extended writing, no graph to draw, no practical to manage — just knowledge and application in its purest form. The data says an A on Paper 2 requires between 30 and 33 correct answers out of 40. That is getting at least 75% of questions right, and based on six consecutive sessions the threshold has never dropped below 30 or risen above 33. This is a narrow, predictable target — and that predictability is a gift. A student who has completed Papers 4 and 6 has already revised the entire syllabus. Paper 2 revision is not about learning new content. It is about tightening accuracy on content already known. The most common Paper 2 errors come from misreading questions, confusing similar biological processes such as mitosis versus meiosis or active transport versus diffusion, and dropping marks on calculation-based MCQs involving photosynthesis rates or population data. Past Paper 2 papers from 2019 to 2025 are available on the Cambridge School Support Hub. Working through them under timed conditions — 45 minutes, 40 questions — and reviewing every wrong answer carefully is the single most effective use of revision time in the days before this paper.
Frequently asked questions
Is the A* boundary getting harder to reach each year?
For the June series, there is a mild upward trend — particularly on Paper 4. The A* overall boundary rose from 164 in June 2023 to 174 in June 2025. However, this reflects a combination of paper difficulty calibration and cohort performance, not a runaway escalation. The boundaries will not suddenly jump to 185 or 190. Students who target 173 to 175 out of 200 as their revision benchmark are working from a sound, data-driven position.
Do grade boundaries differ between Paper 5 and Paper 6?
Yes. Option BY uses Paper 5, which is the actual practical examination, while Option CY uses Paper 6, the alternative to practical. The overall thresholds differ between these options. This guide focuses on Option CY with Paper 6, as it is the route available to most international school students, including those in Kuwait and across the GCC region. Students in schools where Paper 5 is sat should refer to the Option BY boundaries in the official threshold tables.
Can a strong Paper 2 compensate for a weak Paper 4?
Partially, but not fully. Paper 4 carries 80 raw marks versus Paper 2's 40. A student who scores poorly on Paper 4 — well below grade C — and achieves a near-perfect Paper 2 score still has a severely restricted overall total. Paper 4 is the dominant component. The honest message is that Paper 2 can move a grade by one boundary — from B to A, or from C to B — but it cannot bridge a two or three-grade gap caused by a very low Paper 4 performance. Students in that position should be realistic about their target and focus their remaining energy on maximising every available mark across Papers 2 and 6.
When will the June 2026 grade boundaries be published?
Cambridge typically publishes grade threshold tables on the same day as results. For the June series this is usually mid-August. The exact date for August 2026 will be confirmed by Cambridge International closer to the time.
Where can I find the official grade threshold tables?
All official Cambridge IGCSE Biology (0610) grade threshold tables — for June and November sessions going back several years — are published directly at the Cambridge IGCSE grade threshold tables page.
Summary: what every IGCSE Biology student needs to know
The A* boundary for IGCSE Biology (0610) Option CY has ranged between 161 and 174 out of 200 across the past three years and six sessions. Paper 4 is the highest-leverage component — it carries double the marks of Papers 2 and 6 and should receive proportionally more revision time from any student targeting A or A*. Paper 2 thresholds are the most stable of the three papers, with the A boundary never leaving the range of 30 to 33 out of 40 across six consecutive sessions. Paper 6 thresholds are equally predictable, with the A boundary sitting between 30 and 34 in every session. June sessions have trended toward slightly higher A* thresholds than November sessions, though the gap is not always large. For June 2026, a reasonable A* target is 172 to 175 out of 200 — meaning approximately 33 out of 40 on Paper 2, 55 out of 80 on Paper 4, and 33 out of 40 on Paper 6. The official 2026 boundaries will be published by Cambridge International in August 2026. Until then, the data from six sessions gives students the clearest possible picture of where to aim.
Analysis based on official
Cambridge International IGCSE Biology (0610) grade threshold tables for June 2023, November 2023, June 2024, November 2024, June 2025, and November 2025. All data sourced directly from
cambridgeinternational.org. For live IGCSE Biology and Chemistry tuition, revision classes, and study resources, visit
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