A business school can be ranked second in the world on one table and outside the top twenty on another, in the same year, with nothing about the school having changed. That is not a mistake. It is the predictable result of different tables measuring different things. If you are using rankings to choose where to study, it helps to understand how business school rankings work before you let them decide for you. For context on the full range of schools the tables cover, see our guide to business schools in London.
Who publishes the major rankings
A handful of publishers dominate. The Financial Times, QS, Times Higher Education and The Economist each produce their own league tables for MBAs, master's programmes and sometimes executive education. They are separate organisations using separate methods, which is the first reason their results differ. There is no single official ranking of business schools, only competing ones.
What rankings actually measure
Most tables blend a set of weighted factors into a single score. Common ingredients include the salary graduates earn and how much that rises after the course, how quickly people find work, the diversity of the cohort and faculty, the volume and quality of academic research, and survey responses from students or recruiters. The key point is that each publisher chooses which factors to include and how heavily to weight them. A table that weights salary heavily will favour schools whose graduates go into high-paying sectors. A table that weights research will favour large academic institutions. The "best" school is partly a product of what the table decided to value.
Why the same school ranks differently
Once you know the tables use different weightings, the disagreements make sense. One ranking might reward a school for the salary jump its finance graduates achieve, while another barely counts salary and instead rewards research output, where that same school is weaker. Sample size matters too: rankings rely on survey responses, and a low response rate in one year can move a school several places for reasons that have nothing to do with teaching quality. Small differences in score often translate into large-looking gaps in position.
What rankings do not tell you
Rankings are silent on the things that may matter most to you personally. They rarely capture whether a programme is available part time or online, whether the timetable fits around a job, whether the school teaches the specific subject you want, or whether the location and network match your target industry. They also tend to focus on full-time flagship programmes, which means specialist master's, professional diplomas and executive courses are often left out entirely. A school being absent from a ranking does not mean it is weak. It may simply not offer the kind of programme the table measures. For a clear comparison of how different programme formats differ in cost and commitment, read our guide on short courses versus long programmes.
How to use rankings sensibly
Treat rankings as one input among several. Use them to compare similar full-time programmes, not to compare fundamentally different types of study. Read the methodology, or at least check which factors are weighted most heavily, so you know whose priorities the table reflects. Look at the underlying data points that matter to you, such as employment rate or salary in your sector, rather than the headline position. And weigh rankings against the practical questions a table cannot answer: format, cost, subject and fit.
In summary
Business school rankings work by combining weighted factors into a single score, which is why different publishers produce different results for the same school in the same year. They are a useful starting point for comparing like with like, but they reflect the publisher's priorities, not yours, and they ignore the format and cost questions that decide most real choices. Use them carefully, then make the decision on fit. For the full process, read our guide on how to choose a business school in London.