Comprehensive school pupils are more likely to gain a better university degree than those who were educated privately or at grammar schools, research suggests.
A study commissioned by the Sutton Trust also suggests comprehensive pupils are likely to do as well as independent or grammar students who have one or two A-level grades higher.
The research, conducted by the National Foundation for Educational Research (NFER) tracked thousands of A-level students to examine whether the US-based SAT college exam could be used in UK university admissions. But it found the type of school a child attends has a big impact on the outcome of their degree.
The probability of comprehensive students obtaining a 2.1 degree or above is 78%, the study concludes, whereas the probability for students from grammar schools with similar A-level results is 70%. For private school pupils the probability is 63%.
In addition, the probability of comprehensive pupils gaining a first class degree is 10%, dropping to seven percent for grammar students with similar results, and 5% for those from private schools.
The study says: "To look at this in another way, independent or grammar school students who achieve the same level of degree as students from a comprehensive school, with the same GCSE attainment and other background characteristics, are likely to have an average A-level grade that is approximately 0.5 to 0.7 of a grade higher.
"Therefore a comprehensive student with grades BBB is likely to perform as well at university as an independent or grammar school student with grades ABB or AAB."
These differences appear for all types of universities, including those that are more selective, the study says, and it took into account the fact some institutions demand higher grades than others.
The study concluded SAT results are a poorer predictor of degree results than A-levels and GCSEs and that the test does not identify the academic potential of poor students that may be missed by A-levels.
Sutton Trust chairman Sir Peter Lampl said: "These findings provide further evidence that universities are right to take into account the educational context of students when deciding who to admit - alongside other information on their achievements and potential."