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What predicted grades are
An IB predicted grade is the subject teacher's expected final grade for each of the student's six IB Diploma subjects, plus an overall predicted total out of 45 points. The prediction sits on the same 1 to 7 scale as the final grade and is issued by the school before the final IB examinations are sat. The school submits predicted grades to universities directly as part of the university application process. The IB itself also collects predicted grades from schools for moderation and research purposes, although the IB does not publish them.
Predicted grades are different from mock examination grades. Mock grades reflect performance on a specific mock paper sat in school conditions, typically in the autumn or January of Year 12. Predicted grades represent the teacher's expectation of the final external examination result, drawing on mock performance, internal assessment grades, class work and the teacher's professional judgement about the student's likely trajectory. Predicted grades are forward looking; mock grades are backward looking. For the broader IB picture see the IB curriculum explained.
How teachers produce them
The IB does not publish a single mandated methodology for predicted grades. Each school follows its own approach, typically built around four inputs: mock examination performance (the heaviest single input at most schools), internal assessment grades (the IA component of each subject, externally moderated by the IB), class work and homework grades through Year 11 and the first term of Year 12, and the teacher's professional judgement about the student's recent trajectory and expected examination performance.
Different subject teachers weight these inputs differently. Strong schools standardise the approach through a heads of department meeting in September of Year 12, agree the weighting of mock papers and internal assessments, and apply a consistent methodology across the cohort. Weaker schools leave the methodology to each teacher individually, which produces wider variance in prediction accuracy across subjects and between cohorts.
The IB coordinator typically reviews the predicted grades collected from subject teachers, looks for inconsistencies (a student predicted 7 in one subject and 4 in another with no obvious explanation), and resolves them through a discussion with the relevant teacher. The final predicted total is the sum of the six subject grades plus the Theory of Knowledge and Extended Essay bonus point matrix. The cohort wide totals are typically reviewed by the IB coordinator against the previous cohort to check for grade inflation or compression.
The predicted grades timeline
The practical timeline runs through Year 12. September: subject teachers receive mock examination results from the August re mark and the September re sit (where applicable), review internal assessment progress, and prepare initial predictions. October: the IB coordinator collects subject predictions and produces the consolidated predicted grade per student. October to November: UCAS deadlines for Oxbridge (15 October) and the rest of UCAS (typically 25 January) drive the timing of the formal predicted grade submission. The Common Application for US universities accepts predicted grades through the November and January submission windows.
The IB itself collects predicted grades from schools in March of Year 12 for the May examination cohort. These predictions feed into the IB's research on prediction accuracy and inform the standardisation of school predictions across the global cohort. The predicted grades the IB collects are slightly later than the predictions submitted to UCAS, which means the IB collected predictions are typically the more accurate version because they reflect more data. The admission interview questions for parents piece covers the wider application timeline.
Free university application toolkit
Our 16 page IB university application toolkit covers the predicted grades calendar, the UCAS Personal Statement outline, the Common Application essay framework and the predicted grades conversation script for the parent teacher meeting. Use the compare tool to put up to three IB schools side by side on Diploma averages and university destinations. Talk to our team for personal application support.
How universities use them
UK universities make conditional offers based on predicted grades plus the rest of the UCAS application (personal statement, school reference, IGCSE grades). The conditional offer specifies the actual IB Diploma score the student must achieve to confirm their place: Oxford typically asks for 38 to 40 plus specific Higher Level grades, Imperial 38 to 39, LSE 38 to 39, UCL 36 to 38, the wider Russell Group 32 to 36, the post 1992 universities 28 to 32. The predicted grade must usually match or exceed the conditional offer for the offer to be made in the first place.
US universities use predicted grades as one input among many. The Ivy League and top tier US universities give significant weight to the predicted grade alongside the standardised test (SAT or ACT), the GPA equivalent (for IB students typically the unweighted average of the predicted IB subject grades), the supplementary essays, the teacher recommendations and the extracurricular profile. US universities are less rigid about specific predicted grade thresholds than UK universities; a strong overall profile can compensate for a moderate predicted grade. The IB versus AP university outcomes piece covers the US admissions picture in detail.
How accurate they are
Research on IB predicted grade accuracy (the IB's own research and independent analysis) finds that around 60 to 65 per cent of subject predictions exactly match the final actual grade. Of the remaining 35 to 40 per cent of predictions, around 25 to 30 per cent are off by one grade and only 5 to 10 per cent are off by two grades or more. Over predictions (predictions higher than the final grade) are more common than under predictions, with the over to under ratio typically running 2:1 or 3:1.
The accuracy varies substantially between schools. The strongest schools (typically schools that have standardised the prediction methodology and that have a long IB history) post exact match rates of 70 to 75 per cent. The weaker schools (newer to IB or with inconsistent methodology) post exact match rates of 50 to 55 per cent. Schools with a culture of optimistic prediction tend to deliver higher over prediction rates and more disappointed conditional offer outcomes; schools with a culture of conservative prediction tend to deliver more accurate predictions and stronger conditional offer conversion. Both approaches have trade offs.
| Prediction outcome | Share at typical school | Share at strong school |
|---|---|---|
| Exact match | 60 to 65 per cent | 70 to 75 per cent |
| Over predicted by 1 | 20 to 25 per cent | 15 to 18 per cent |
| Under predicted by 1 | 8 to 10 per cent | 7 to 9 per cent |
| Over predicted by 2 or more | 4 to 6 per cent | 1 to 3 per cent |
| Under predicted by 2 or more | 1 to 2 per cent | 1 per cent |
When predictions and final grades diverge
The implications of an over predicted grade are real. A student predicted 7 in Higher Level mathematics who actually scores 5 will miss the Cambridge engineering conditional offer (which requires 7 in HL maths). The student has three options: take the offer at the insurance university (typically a less competitive university with a lower conditional offer), apply through UCAS Adjustment to a higher tariff university with available places, or take a gap year and reapply with the actual grade in hand. None of these is a perfect outcome and most over predictions cause real disruption to university plans.
Under predictions are less disruptive but still costly. A student predicted 35 who actually scores 38 may have applied to universities with conditional offers around 33 to 35 rather than the more selective universities the higher grade would have supported. Under predictions are difficult to correct after the fact; UCAS Adjustment exists but the available places at higher tariff universities are usually limited. The right response is to apply early to a wider range of universities and treat the conditional offers as a portfolio.
What to do if predicted grades look low
If predicted grades look out of line with your child's recent performance, the first step is a conversation with the relevant subject teacher. Ask for the specific evidence behind the prediction: mock paper performance, internal assessment grade, class work track record, the teacher's expected trajectory. Be specific about the evidence the family sees that suggests a higher prediction is warranted: a strong run of recent assessment grades, a strong internal assessment that has not yet been moderated, a specific mock examination that may have been atypically low.
If the teacher's case is reasonable and rests on objective evidence, the prediction is likely defensible. If the teacher is not able to articulate a clear evidence base, escalate to the IB coordinator. Schools can and do revise predicted grades in the autumn of Year 12 before formal submission to universities, although the bar for revision is high. After formal submission to UCAS the prediction is fixed; only an internal upgrade procedure exists for material errors. The switching schools piece covers the rare but workable option of moving school in Year 12 if the prediction culture is materially out of line with the family's expectations.
Choosing a school with good prediction practice
When shopping for an IB school, ask explicitly about prediction practice. Questions: what proportion of last year's predicted grades exactly matched the final actual grade (anything below 60 per cent should give pause); how does the school standardise predictions across subject teachers; what is the schedule for predictions and the conversation with parents; what does the school do if predictions look out of line. Strong schools answer these questions openly with specific data; weaker schools deflect or generalise.
The how to choose an international school piece covers the broader school selection framework and the university counselling at international schools piece covers the related question of how well the school supports the application process itself.
Related guides
Frequently asked questions
What are IB predicted grades?
IB predicted grades are the subject teacher's expected final grade for each of the student's six IB Diploma subjects, plus an overall predicted total out of 45 points. They are submitted to universities as part of the university application process, before the final IB examinations are sat.
When are IB predicted grades issued?
Predicted grades are typically finalised by IB schools in October or November of Year 12 for UCAS and Common Application submissions. The IB itself collects predicted grades from schools for moderation purposes in the spring of Year 12.
How accurate are IB predicted grades?
Around 60 to 65 per cent of IB predicted grades exactly match the final actual grade, with most of the remaining predictions within one grade of the final result. Over predictions are more common than under predictions at most schools.
What if my child's predicted grade is too low?
Speak with the subject teacher and the IB coordinator first. Predicted grades are based on mock examination performance, internal assessments and class work, and a discussion of specific evidence can sometimes lead to a revised prediction.