That is according to a new report by the Sutton Trust, Earning by Degrees, which says that the average starting salary for an Oxbridge graduate is £25,582, compared with £18,009 for alumni of new universities.
The research, based on data from the Higher Education Statistics Agency, puts the mean wage six months after graduation at £21,031 for what the Sutton Trust classes as the UK’s 28 other most selective universities, and £19,684 for other pre-92 institutions.
Stark inequalities persist even when the figures are adjusted to take account of factors such as socio-economic background, previous educational attainment and attendance at private or state school.
When these are factored in, the average starting salary of an Oxbridge graduate is £23,613, which is 25 per cent higher than the £18,853 wage that students of post-92 universities can expect once they leave.
Peter Lampl, the chairman of the Sutton Trust, said more had to be done to raise the aspirations and attainment of school students from poorer backgrounds.
“This new research shows how important it is that we enable low- and middle-income students with the ability to go to Oxbridge and other elite universities to fulfil their potential,” he said.
“With your chances of going to a top university nearly 10 times higher if you come from a rich rather than a poor neighbourhood, it is vital that we redouble our efforts to improve access to these institutions.”
The report, published on 17 December, also looks at the starting salaries of graduates according to the course they studied.
It says that engineering and technology graduates will earn £8,800 (55 per cent) more on average than design and creative arts graduates, and £8,000 (49 per cent) more than English students.
A science or engineering graduate from Oxbridge is likely to command a starting salary £11,800 higher than a graduate in an arts or humanities subject from a post-1992 institution.
The report also says that graduates who attended fee-paying secondary schools earned average starting salaries £1,300 higher than their state school educated counterparts.