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The Computer Science Tripos (CST) is aimed at students who wish to concentrate their studies on Computer Science to the maximum extent possible. In the first year, 75% of the coursework prepares the student for three papers on various aspects of Computer Science and the remaining 25% is devoted to a Mathematics course that is held in common with other subjects. In subsequent years, courses are all on various aspects of Computer Science, with scope for substantial specialisation in the third year.

Frank Stajano, one of Trinity’s Directors of Studies in Computer Science, explains the admissions process and gives some tips to prospective applicants.

Course Details

Course length: 4 Years
Typical offer: A*A*A
Preferred A-Level subjects: Maths, Further Maths and Physics


Optional fourth year

The CST course is a three-year BA degree. It is however possible to apply to continue studying Computer Science into a fourth year, provided a sufficiently high standard is achieved in the third-year examination. The course then leads to the MEng degree in addition to the BA achieved in the three-year course. If necessary – for example in dealing with your funding body – it would be wise to indicate that the length of the course is four years, or three/four years, to allow for all possibilities.

Further information on the CST Tripos

Please see for further information hosted by the Department of Computer Science and Technology website.  In particular, you may find information there on the detailed structure of later years of the CST.

CST in Trinity

Trinity’s Directors of Studies in Computer Science are: Dr Sean Holden, whose research interests include machine learning, Bayesian inference, automated theorem proving and artificial intelligence; Professor Frank Stajano, who focuses on security, privacy, human factors and entrepreneurship; and Professor Neel Krishnaswami, whose research interests lie at the intersection of program verification, programming language design and logic, semantics and type theory. All of them have chosen to make videos of their courses available to all: visit their YouTube channels (Dr HoldenProfessor Stajano, Professor Krishnaswami) to experience some genuine Cambridge Computer Science lectures before you even get here. In addition, Trinity has two Post-Doctoral Teaching Assistants in CST, Dr Jonathan Woodruff, and Dr Zheng Yuan, who assist us in providing undergraduate supervisions.

Student rooms provide network connections allowing access to email, the web and all major computing facilities around the University. There are also well-equipped computer rooms which provide access to scanners, laser printers and where the bulk of the machines can be re-set to run either Windows or Linux.

Interview and written tests

Candidates will sit a written assessment (pre-registration required) before being shortlisted for interview. This is called the Test of Mathematics for University Admission (TMUA) and details including sample test papers can be found here:

The Test of Mathematics for University Admission (TMUA)

Those invited to interview will then have a 45-minute interview with two people, at least one of whom will be a Director of Studies. Immediately before this interview candidates will sit a second test called the Computer Science Admissions Test (CSAT), and the interview will involve a discussion of their progress through the CSAT. Details regarding the CSAT, including advice on how to prepare and sample questions, can be found here.

Please note that your performance in the written assessments and interview will not be considered in isolation, but will be taken into account alongside the other elements of your application.

Preparatory online course

Before arriving in October successful candidates will be required to complete an online pre-arrival course. Details regarding the organization of this course will follow later in the admissions process.


Conditional offers for the CST will typically be A*A*A including Mathematics and two other science subjects (preferably Physics and Further Mathematics); we may also ask for a high grade in a relevant subject taken at only AS level.

Comparable conditions are set for those taking the IB and other school-leaving examinations. We make on average 12 offers for admission per year.

For the avoidance of doubt, the 75% course is the only one available.  Older courses allowing the study of a Natural Science subject in the first year are no longer available.

Admissions Assessment

All applicants are required to take The Test of Mathematics for University Admission (TMUA), see the written assessments page for further information.

You must be registered in advance (separately to your UCAS application) to take the test – the online registration deadline is 16 September 2024. See the written assessments page for further information.

You will take the test on 16 or 17 October 2024.  You must take the test in the first sitting.

Please note that your performance in the TMUA will not be considered in isolation, but will be taken into account alongside the other elements of your application.

Teaching Staff

  • Dr Sean Holden
  • Professor Neel Krishnaswami
  • Professor Frank Stajano
  • Dr Jonathan Woodruff
  • Dr Zheng Yuan

Trinity CS undergraduate Ana Dolinar tells of her experience here, in the context of an ongoing series of outreach interviews on the Frank Stajano Explains channel.

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