The primary aim of the QS World University Rankings® is to help students make informed comparisons between their international study options. Since first being compiled in 2004, the rankings have expanded to feature more than 800 universities around the world, with far more (over 3,000) assessed. The top 400 universities are given individual ranking positions, and after this universities are placed within a group, starting from 401-410, up to 701+.

The rankings compare these top 800 universities across four broad areas of interest to prospective students: research, teaching, employability and international outlook.

These four key areas are assessed using six indicators, each of which is given a different percentage weighting (see below). Four of the indicators are based on ‘hard’ data, and the remaining two on major global surveys – one of academics and another of employers – each the largest of their kind. Below is a guide to each of the six indicators used.

1. Academic reputation (40%)

Academic reputation is measured using a global survey, in which academics are asked to identify the institutions where they believe the best work is currently taking place within their field of expertise.

For the 2014/15 edition, the rankings draw on almost 63,700 responses from academics worldwide, collated over three years. Only participants’ most recent responses are used, and they cannot vote for their own institution. Regional weightings are applied to counter any discrepancies in response rates.

The advantage of this indicator is that it gives a more equal weighting to different discipline areas than research citation counts. Whereas citation rates are far higher in subjects like biomedical sciences than they are in English literature, for example, the academic reputation survey weights responses from academics in different fields equally.

It also gives students a sense of the consensus of opinion among those who are by definition experts. Academics may not be well positioned to comment on teaching standards at other institutions, but it is well within their remit to have a view on where the most significant research is currently taking place within their field.

2. Employer reputation (10%)

The employer reputation indicator is also based on a global survey, taking in almost 28,800 responses for the 2014/15 edition. The survey asks employers to identify the universities they perceive as producing the best graduates. This indicator is unique among international university rankings.

The purpose of the employer survey is to give students a better sense of how universities are viewed in the job market. A higher weighting is given to votes for universities that come from outside of their own country, so it’s especially useful in helping prospective students to identify universities with a reputation that extends beyond their national borders.

3. Student-to-faculty ratio (20%)

This is a simple measure of the number of academic staff employed relative to the number of students enrolled. In the absence of an international standard by which to measure teaching quality, it provides an insight into the universities that are best equipped to provide small class sizes and a good level of individual supervision.

4. Citations per faculty (20%)

This indicator aims to assess universities’ research output. A ‘citation’ means a piece of research being cited (referred to) within another piece of research. Generally, the more often a piece of research is cited by others, the more influential it is. So the more highly cited research papers a university publishes, the stronger its research output is considered.

QS collects this information using Scopus, the world’s largest database of research abstracts and citations. The latest five complete years of data are used, and the total citation count is assessed in relation to the number of academic faculty members at the university, so that larger institutions don’t have an unfair advantage.

5 & 6. International faculty ratio (5%) & international student ratio (5%)

The last two indicators aim to assess how successful a university has been in attracting students and faculty members from other nations. This is based on the proportion of international students and faculty members in relation to overall numbers. Each of these contributes 5% to the overall ranking results.

Alongside the main QS World University Rankings®, the QS World University Rankings by Faculty are also published. These provide rankings of the world’s top 400 universities in five broad faculty areas: arts & humanities, engineering & technology, life sciences & medicine, natural sciences, and social sciences & management. These rankings use an adapted methodology, drawing on the academic and employer surveys, as well as citations data.

View the latest edition of the QS World University Rankings >