1. Start with component points
A subject may contain Paper 1, Paper 2, Paper 3, an internal assessment, an oral, a portfolio, or another subject-specific task. Each component has its own maximum mark. A score of 30 on a 40-mark paper is 75% for that component.
2. Apply the assessment weighting
If that component is worth 40% of the final subject result, a 75% component performance contributes 30 weighted percentage points:
(30 ÷ 40) × 40 = 30
The same calculation is repeated for every component. The weighted contributions are then added to produce the estimated final subject percentage.
3. Apply the correct grade boundary
The weighted percentage is matched to the grade boundary for the subject, level, examination session, and where relevant time zone. Boundaries can differ between subjects and sessions, so a 70% result does not automatically mean the same grade everywhere.
Worked example
| Component | Points | Component result | Weight | Contribution |
|---|---|---|---|---|
| Paper 1 | 30 / 40 | 75% | 36% | 27.0 |
| Paper 2 | 44 / 60 | 73.3% | 44% | 32.3 |
| Internal assessment | 18 / 24 | 75% | 20% | 15.0 |
| Estimated weighted percentage | 74.3% | |||
The final 1–7 grade depends on the matching boundary set. The example demonstrates the method, not a universal boundary.
Why level and time zone matter
SL and HL may have different components, maximum marks, or boundaries. Time-zone papers can also have different boundaries. The calculator’s global time-zone control filters subject combinations to reduce accidental mixing, while TZ0 subjects remain available across zones.
Predicted grades and official grades
This calculator produces an estimate from entered marks and stored boundaries. A school predicted grade may use teacher judgement and evidence beyond one examination calculation. An official IB grade is issued only through the formal assessment process.
Always match the subject name, syllabus, level, session, and time zone before relying on an estimate.