IB Biology Grade Boundaries
View IB grade boundaries for Biology HL and SL across recent and past exam sessions. Compare historical changes in grade boundaries and explore detailed statistics, including candidate numbers and grade distributions.
Points needed
| Grade | Paper 1A | Paper 1B | Paper 2 | Practical Work | Final Grade |
7 | 24-30 | 19-25 | 33-50 | 20-24 | 72-100% |
6 | 22-23 | 16-18 | 26-32 | 17-19 | 60-71% |
5 | 20-21 | 13-15 | 19-25 | 14-16 | 48-59% |
4 | 18-19 | 10-12 | 12-18 | 11-13 | 36-47% |
3 | 15-17 | 7-9 | 7-11 | 7-10 | 24-35% |
2 | 8-14 | 4-6 | 4-6 | 4-6 | 13-23% |
1 | 0-7 | 0-3 | 0-3 | 0-3 | 0-12% |
Biology Grade Boundaries Over Time
Historical Thresholds
| Session | 7 | 6 | 5 | 4 | 3 | 2 |
| Nov 25 | 78% | 66% | 52% | 40% | 25% | 14% |
| May 25 | 77% +1 | 64% ±0 | 52% ±0 | 39% -1 | 26% ±0 | 13% -1 |
| Nov 24 | 76% | 64% | 52% | 40% | 26% | 14% |
| May 24 | 76% | 64% | 52% | 40% | 27% | 15% |
| Nov 23 | 78% | 65% | 52% | 39% | 27% | 15% |
| May 23 | 76% | 64% | 51% | 39% | 26% | 15% |
| Nov 22 | 78% | 65% | 51% | 39% | 26% | 15% |
| May 22 | 79% | 64% | 49% | 34% | 24% | 14% |
| Nov 21 | 77% | 63% | 47% | 35% | 23% | 14% |
| May 21 | 74% | 60% | 44% | 32% | 21% | 12% |
| Nov 20 | 75% | 63% | 51% | 39% | 26% | 15% |
| Nov 19 | 79% | 66% | 55% | 42% | 27% | 15% |
| May 19 | 78% | 66% | 54% | 43% | 31% | 17% |
Session Snapshot
Total candidates
21,564
Highest grade %
5.6%
Grade Distribution
Grade 7
5.6%
Grade 6
12.9%
Grade 5
21%
Grade 4
24.6%
Grade 3
22.4%
Grade 2
9%
Grade 1
1.5%
N
2.9%
Frequently Asked Questions
Are the Biology grade boundaries the same every year?
No. IB grade boundaries can change from one exam session to another. The IB reviews the difficulty of each examination and adjusts boundaries to ensure grading standards remain consistent over time. As a result, the score needed for a particular grade in Biology may be slightly higher or lower than in previous years.
How accurate are those Biology grade boundaries?
The grade boundaries for Biology shown on this page are taken directly from official documents published by the International Baccalaureate (IB). They reflect the official grade boundaries used for the selected examination session and can be considered fully accurate.
Are Biology grade boundaries the same worldwide?
Not completely. The IB uses different exam time zones (typically TZ1 and TZ2) for some subjects, and students in different time zones may sit different paper variants. In these cases, grade boundaries are set separately for each time zone and paper combination, so they can differ slightly. However, within the same time zone and exam version, all students are graded using the same grade boundaries.
What score do I need to get a 7 in Biology?
To achieve a grade 7 in Biology, you need at least 72 out of 100 marks (72%) in this exam session, according to official IB grade boundaries.
What is considered a good score in IB Biology?
Most universities consider a grade 6–7 in IB Biology a strong result. A 7 is excellent, a 6 is very strong, and a 5 is a solid pass demonstrating good understanding.
How are Biology grade boundaries calculated?
Grade boundaries are set after marking based on student performance in that exam session. The IB adjusts them each year so that grades reflect overall performance: if an exam is harder, boundaries are lowered, and if it is easier, boundaries are raised. This ensures a consistent distribution of grades across different sessions.
Can I use these Biology grade boundaries to predict my final grade?
Yes. Grade boundaries can be a useful tool for estimating your final grade if you know your likely marks on each assessment component. However, predictions are never guaranteed because your final result depends on your actual Biology exam and coursework scores, as well as the official grade boundaries for your exam session.
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