Researchers have worked out a scale of subject difficulty using the GCSE results of 650,000 pupils from 2004.
They say a student might get a grade higher if they opted for drama or media studies over chemistry or German.
The findings - by Dr Robert Coe at Durham University – were highlighted just as a report on the teaching of languages in schools is about to be released.
The report, by Sir Ron Dearing, is due on Monday. It is expected to come out in favour of all children being taught languages at primary school.
There is concern about the falling numbers of teenagers opting to do modern foreign languages - which are no longer compulsory in secondary schools after the age of 14.
Last year there was a 14% fall in the number of entries for German at GCSE and a 13% drop in those for French.
For the Durham study, carried out at the university's educational research unit, the CEM Centre, researchers looked at children's academic abilities and their results in various subjects.
'Eesier' subject are Sport/PE, Textiles, Drama, Media studies, English, Office technology and Food technology
