Real May 2025 IB grade boundaries for Chemistry SL/HL, Math AI HL, Psychology HL and Global Politics SL/HL, plus a calculator that converts your mark out of 100 to a 1–7 grade.
| Input | Result |
|---|---|
| 72 out of 100 — Chemistry HL | grade 6 |
| 80 out of 100 — Mathematics AI HL | grade 7 |
| 20 out of 100 — Psychology HL | grade 3 |
| 55 out of 100 — Global Politics SL | grade 6 |
IB grade boundaries are not the same for every subject, every level, or every session — they are produced separately each exam session after candidates have been graded. Enter your weighted total mark out of 100, then pick a subject and level to see the May 2025 bands for it.
These figures are the May 2025 session boundaries as published in the IB's grade boundary documents for these subjects. They are real data, not interpolated — but they describe one session only.
| Grade | Chemistry HL | Chemistry SL | Math AI HL | Psychology HL | Global Politics SL | Global Politics HL |
|---|---|---|---|---|---|---|
| 7 | 77–100 | 71–100 | 77–100 | 72–100 | 65–100 | 71–100 |
| 6 | 64–76 | 60–70 | 65–76 | 60–71 | 55–64 | 59–70 |
| 5 | 52–63 | 49–59 | 52–64 | 47–59 | 44–54 | 48–58 |
| 4 | 40–51 | 38–48 | 39–51 | 35–46 | 35–43 | 36–47 |
| 3 | 27–39 | 28–37 | 28–38 | 20–34 | 24–34 | 24–35 |
| 2 | 16–26 | 16–27 | 15–27 | 9–19 | 11–23 | 11–23 |
| 1 | 0–15 | 0–15 | 0–14 | 0–8 | 0–10 | 0–10 |
Look at how differently the same mark is treated. A 70 out of 100 is a grade 7 in Global Politics SL, a grade 6 in Chemistry HL and a grade 4 in Psychology HL. Nothing about those candidates is being judged differently — the papers, the mark schemes and the cohort are. This is the single most important thing to understand about IB boundaries: they are a ranking device, not a fixed percentage.
The practical consequence for revision is that you should never aim at a percentage. Aim at a mark band for your subject and session, then translate that into raw marks per paper using the component breakdown your teacher has.
After each exam session the IB runs grade award meetings. Examiners look at the difficulty of the papers, the performance of the cohort and how the results compare with previous sessions, then set the mark that separates a 6 from a 7 for each subject and level. Sessions with harder papers tend to have lower boundaries, and sessions with easier papers higher ones. That is deliberate: it keeps a grade 6 in Chemistry worth roughly the same year on year, so universities can trust it.
This is also why the boundaries in an online table should always be treated as a planning tool rather than a target. A boundary published for one session can sit five or six marks away from the next session's — which on a component out of 24 is more than a whole grade.
Your total out of 100 is a weighted blend of internal assessment and exam papers, and the components have very different mark counts. In Chemistry HL the Internal Assessment is marked out of 24 while Paper 2 is out of 90, so a single mark lost in the IA is worth proportionally more of that component. When you are close to a boundary, look at the component breakdown: the cheapest marks to recover are almost always in the IA, because you write it over months with feedback rather than under exam pressure.
| Commonly confused | Reality |
|---|---|
| "The IB pass mark is 24" | 24 points is the total-points condition only — five further distribution conditions and the CAS requirement also apply |
| TOK and the Extended Essay have 1–7 boundaries | No — they are graded A–E and combine into 0–3 core points through a matrix |
| There is one set of boundaries per subject | No — HL and SL are bound separately, because they are different papers and different cohorts |
| A boundary table is valid for your session | Only until the next session; boundaries are re-set at each grade award |
If you want the total out of 45 rather than a single subject grade, use the IB grade calculator, which applies the official TOK/EE matrix and checks all nine diploma conditions.
They are the mark ranges that separate each grade from 1 to 7, set separately for every subject, every level and every exam session. Your weighted total out of 100 falls into one of seven bands, and that band is your grade.
No. Unlike A-levels or many national systems, the IB does not publish a permanent percentage for each grade. Boundaries are decided at the grade award meeting after each session, based on paper difficulty and cohort performance, so a mark of 70 can be a 7 in one subject and a 4 in another.
For May 2025: 77 out of 100 in Chemistry HL, 71 in Chemistry SL, 77 in Mathematics Applications and Interpretation HL, 72 in Psychology HL, 65 in Global Politics SL and 71 in Global Politics HL. Other subjects and other sessions differ — always check the boundary document for your own subject.
No, they are set separately because they are different papers taken by different cohorts. In May 2025 Chemistry, a 7 started at 77 out of 100 at HL but 71 at SL — the SL paper is shorter and the boundaries reflect that.
The IB publishes grade boundary documents for each exam session, and your school's DP coordinator receives them. Published tables circulating online are usually reproductions of those documents for one session, which is exactly what the May 2025 figures on this page are.
Use them to plan, not to predict. They show you the scale of the task and where the boundaries sat, but the next session's boundaries depend on papers you have not seen and a cohort you are not in. Treat the number as a target with a margin of several marks.
Only as far as total points go. The diploma also requires at least a grade 2 in every subject, no more than two grade 2s, no more than three grades of 3 or below, at least 12 points across HL, at least 9 across SL, no E in TOK or the Extended Essay, and completed CAS.