IB grade boundaries calculator for retake planning

Use past IB grade boundaries to decide whether a retake target is realistic. Pick a session, search for your subject and level, then test the marks you would need before you commit time, travel, and money to another exam session.

A two-mark gap is not a forecast

If a historical grade-6 boundary were 65 and your final subject mark were 63, the gap would be 65 − 63 = 2 marks. These are illustrative numbers, not boundaries for a named subject.

1. Match the subject, HL/SL, session and any relevant assessment variant.
2. Match the scale: do not compare raw paper marks with a weighted subject boundary.
3. Check the lower boundary too: a review can move a grade down.
4. Keep historical data historical: a future paper can have a different boundary.

If an illustrative target is 65 and timed practice produces weighted scores of 61, 64 and 62, none yet reaches that target. Identify the recurring lost marks rather than expecting a boundary change to fix the gap. This exercise measures preparation; it does not estimate your probability of passing.

The weighted-mark example explains component contributions. For an actual result, check the review deadline; for a new session, use the study plan. The calculator is a historical planning tool, not your official result.

Understanding IB Grade Boundaries

Grade boundaries are the minimum marks needed to achieve each grade from 1 to 7 in an IB subject. They are set after each session by the IB and vary between sessions, timezones, and subjects.

Match the assessment variant

• TZ0 (Worldwide): Used for subjects with a single paper set globally (e.g. Visual Arts, TOK).
• TZ1 (Americas): North and South America.
• TZ2 (Europe, Africa, Asia Pacific).

How to use the historical calculator

1. Select a session: pick from May or November, covering 2017 to 2025.
2. Search for your subject: type in the search box. You can include the level (HL / SL) and timezone (TZ1, TZ2) to narrow results.
3. Drag the slider: enter your overall mark. The grade associated with that mark in the selected historical dataset updates live.

What past boundaries cannot tell you

• Use boundaries from the same session type you're taking (May for May candidates).
• A November paper does not automatically have a higher boundary than a May paper.
• Do not assume one examination zone is easier: compare the exact assessment and syllabus rather than ranking zones.
• Check you're using the correct syllabus year because some subjects changed syllabuses recently.