IB Physics SL grade boundaries: what you need for a 7

In May 2025 TZ3 a 7 needed 83% on the internal assessment and 56% on Paper 1A (multiple choice). The paper with the lower threshold is the paper that students found hard, and it is usually the one where a few marks are cheapest to gain.

In every session with a full IB document, the internal assessment has had the highest threshold of all the components. It is marked against criteria known in advance, so it is the one part of the grade that is under the student's control before the exam. Which exam paper has the lowest threshold changes from session to session, so a past paper should be marked against the boundaries of its own session.

In Physics SL the 6 sits on average 10.8 marks below the 7 on the 100-mark scale. That is roughly one long question answered fully instead of half-answered, or the marks lost to arithmetic slips and unread instructions across a whole paper.

Students who miss a 7 rarely miss it on content. They miss it on the last part of long questions, on rounding and units, on reading what was asked. The page on the mistakes examiners flag most often in Physics lists where those marks go, and the examiner reports go through every paper, session by session.

May 2025 was the first session of the current Physics syllabus. Paper 3 disappeared and Paper 1 became Paper 1A (multiple choice) and Paper 1B (data analysis). Boundaries before and after that session are not on the same paper structure, which is why the component table above shows a single session.

November 2024 was the last session of the old syllabus. Overall boundaries are still comparable across the change, because the 100-mark scale and the meaning of a 7 did not change.

Use the range, not the last session. A student who is scoring 73% or more on full mocks under exam conditions has a 7 in every session on record. A student at 58% has a 7 only on the hardest paper, and should plan for the 6 to 7 gap rather than assume it.

Mock papers should be marked on the component boundaries of a documented session, not on the overall. Then the weakest component is visible and the revision plan writes itself.

27 of the 30 sessions were read from the grade boundaries document the IB issues to Diploma coordinators. Most of those documents list every component; the most recent one on record lists the overall only. The rows marked “reported” give the overall boundary only, from published compilations of the IB subject reports, and will be checked against the document when it is in hand.

Independent work, not endorsed by the International Baccalaureate. Last reviewed 23 September 2026. Corrections: pietro@pietromeloni.com.