What you will find on this page
- The headline number every school publishes, and what it hides
- Average IB score, the metric to read carefully
- Pass rates, bilingual diploma rates and the rest
- Three-year trajectory, the most useful single signal
- Cohort size and the problem of small samples
- Comparing schools across different cities
- Five questions to ask an admissions office
- Frequently asked questions
The headline number every school publishes, and what it hides
Almost every IB World School publishes an average diploma score and a pass rate at the end of each results cycle. Parents reading marketing materials see "average score 36" or "100 percent pass rate" and treat it as a clean comparison metric. It is not. The schools you are comparing are different in three structural ways: they admit different children, they teach different curricula alongside the IB, and they report their numbers using different conventions. The job for a parent reading IB results is to read past the headline figure and into the structure that produced it.
The world average for the IB Diploma in recent cycles has been close to 30 points out of 45. A score of 36 is roughly the 80th percentile. A score of 40 is roughly the 95th percentile. Schools advertising averages of 38 to 40 are publishing genuinely strong results, but they are doing so against an entry intake that is often equally selective. Whether the school added value, or whether it simply selected high-performing pupils into the diploma in the first place, is the harder question, and the more important one.
Average IB score, the metric to read carefully
The average diploma score, reported as a number out of 45 (24 to 45 in practice, with very few candidates above 42), is the cleanest single metric a school can publish. It is comparable across years and across schools in a way that pass rates and university destinations are not. It is the number to anchor on. But two adjustments matter before you treat it as gospel.
The first is the proportion of the year group that sat the full diploma. A school where 60 percent of the year group took the diploma and averaged 38 is producing different results from a school where 95 percent of the year group took the diploma and averaged 36. The first school has selected the strongest pupils into the diploma and pushed weaker pupils into IB Course candidate status, A-Levels or away from the IB entirely. The second school is running the full diploma at scale. Neither is automatically better; both are valid choices. But a parent comparing the two on average score alone is not comparing like with like.
The second is the bilingual diploma proportion. A bilingual diploma sits above a standard diploma in the IB framework and is awarded only when a candidate passes two language A subjects. Schools with high bilingual diploma rates are typically schools with strong language teaching and significant non-anglophone enrolment. The bilingual diploma rate is a useful secondary signal of curricular depth and of the cohort's linguistic profile.
Pass rates, bilingual diploma rates and the rest
The pass rate is the proportion of candidates who achieved the 24-point threshold for the diploma. The world pass rate sits at around 80 percent. A pass rate above 95 percent is genuinely strong. A pass rate of 100 percent over multiple cycles is exceptional and usually indicates significant selection at the point of entry into Year 12. A pass rate below 85 percent is a useful flag for closer inspection. It is rarely a deal-breaker in isolation; it is a question.
The bilingual diploma rate, the diploma with distinction proportion (40 points and above), and the highest single score in the cohort are the three secondary metrics worth checking. A school that publishes all four metrics openly is a school confident in its data. A school that publishes only the headline average is a school whose admissions team is comfortable with selective disclosure. Both can be excellent schools. The disclosure pattern is itself a signal worth weighing.
Compare IB schools side by side
Use our school comparison tool to put up to three IB schools next to each other on average score, pass rate, cohort size and university destinations. Open the compare tool
Three-year trajectory, the most useful single signal
A single year of IB results tells you very little. A three-year trajectory tells you a lot. Schools that have averaged 35, 36, 37 across the past three cycles are on a different path from schools that have averaged 38, 36, 34. The trend matters more than the point estimate. Ask the admissions office for results for the past three diploma cycles, broken out as average score, pass rate and bilingual diploma rate.
Schools that decline to provide three-year data are usually doing so because a recent strong year is being used to anchor the marketing while earlier years were materially weaker. Schools whose results are genuinely improving will usually provide the trajectory willingly because the trend tells a flattering story. Schools whose results are stable will provide it because the stability is itself reassuring. A trajectory request is one of the most efficient questions you can put to a school.
For broader benchmarking, our ranking of the top 50 international schools in the world and our top 20 in Asia include three-cycle IB averages where the schools publish them.
Cohort size and the problem of small samples
IB cohort sizes at international schools vary from around 15 candidates at small schools to more than 200 at the largest. Cohort size matters because small cohorts produce noisy results. A small school with a cohort of 20 will see its average move two or three points year to year on the strength or weakness of a handful of candidates. The same shift at a school of 150 would require a structural change in teaching or admissions. Small-cohort schools are not worse, but their headline averages are less reliable as a forward-looking signal.
This is one reason that comparing a tier-1 anchor school with 180 IB candidates against a boutique school with 24 is misleading. The boutique school may be excellent. Its average is simply less informative. If you are looking at a small-cohort school, ask for the median, the interquartile range, and the spread of university destinations rather than the average alone. Schools with strong governance can usually provide this in a short table on request.
Comparing schools across different cities
IB results are not entirely city-neutral. Schools in cities with stable, long-term expatriate communities (Geneva, Vienna, Singapore, Hong Kong) tend to produce more consistent IB results than schools in cities with high family turnover (Dubai, Doha, parts of South East Asia). The difference is not curriculum quality, it is cohort continuity. A child who has been at a school since Year 7 will typically outperform a child who joined the diploma cohort in Year 12, all else equal. Schools in high-turnover markets are not worse, but the IB cohort they teach is structurally different.
When comparing schools across cities, also weight the broader context: cost of living, school fee level, alternative curriculum options. Our pieces on Dubai versus Singapore school costs and London versus New York set the fee context that IB results sit inside. A strong IB programme at a 30 percent lower fee point can be the better choice on lifetime family economics, even where the headline average is one or two points lower.
Five questions to ask an admissions office
Five questions cut through marketing material and get to the real picture. The first is the three-cycle average score, the three-cycle pass rate and the three-cycle bilingual diploma rate. The second is the proportion of the year group that took the full diploma, the IB Course Candidate route, or a different qualification entirely. The third is the cohort size for the most recent cycle. The fourth is the highest and lowest individual scores in the most recent cycle, which tells you about the spread. The fifth is the proportion of leavers who matriculated to their first-choice university.
Schools that answer these five questions in writing, with full numbers, are running a transparent IB programme. Schools that paraphrase or redirect are doing something else. Either may be the right school for your child, but the answer pattern is itself a useful filter. Print the five questions, take them to every tour you do, and you will have a comparison sheet at the end of the search that is far more useful than the glossy brochure each school will send you.
Reading subject-level scores, not just the overall
The headline diploma score hides a great deal of subject variance. A 36 with three 7s at higher level and three 5s at standard level is a different academic profile from a 36 with six 6s. Universities, particularly in the UK and increasingly in the US, look at the subject profile as carefully as the total. Strong schools publish subject-level distributions in their results communications. Weak schools do not. Ask for the subject-level mean and the proportion of 7s by subject for the past two cycles. Schools that report this openly are running a transparent academic operation, and the data lets families understand whether the school's strength is concentrated in specific subjects (which may or may not align with the child's intended degree) or spread across the curriculum.
For families targeting medicine or engineering, the science subject means matter more than the school average. For families targeting humanities or social sciences, the language A scores and the history or economics scores matter more. The headline figure does not tell you which strength the school has. The subject breakdown does.
Frequently asked questions
Is an IB average of 36 actually good?
Yes. The IB world average has sat close to 30 over the past five cycles. A 36 average puts a school in the top 20 percent globally. A 38 or above is genuinely strong. Anything above 40 is exceptional and usually accompanied by significant selectivity at the point of entry into Year 12.
How can I get IB results data the school does not publish?
Ask in writing for the three most recent cycles of average score, pass rate and cohort size. Most schools will provide this on request even where it is not on the website. If a school declines, that itself is a useful data point.
Do top universities only look at the final score?
No. Top universities look at predicted grades, the score profile across higher and standard level subjects, the extended essay grade and the theory of knowledge grade, in addition to the headline diploma points. A 36 with three sevens at higher level reads differently from a 36 with three sixes at higher level.
Is a small IB cohort a problem?
Not in itself. Small cohorts offer more individual attention. They also produce noisier results year to year and a narrower spread of subject options. For families weighting subject choice heavily, scale tends to matter more than for families weighting pastoral support.