Marco Común Europeo de Referencia para las Lenguas: Aprendizaje, Enseñanza, Evaluación http://cvc.cervantes.es/OBREF/marco/cvc_mer.pdf (pp. 26-39)
Many times my students have asked me "what is my actual level of English?", and as simple as it should be for me to answer this question, I must admit one gets "out of words" when trying to satisfy this query. Students are so familiar with the traditional terms: beginners, elementary, intermediate (low- and upper-), advanced that to them the frontiers are rather blurred.
Yes, ok, there's certainly a difference between beginners and intermediate, but not that easy when finding the precise line between beginners and elementary, or between upper-intermediate and advanced.
To make matters worse, the two most valued institutions to learn English here in Spain: Escuela Oficial de Idiomas (Official Language School) and The British Institute organize the English route in different levels. I suggest clicking on both links if you want to find out more about it:
http://www.eoidiomas.com/web/Idiomas/ingles.html
http://www.britishcouncil.org/spain-learn-english-in-spain-madrid-adults-general-courses.htm
The Common European Framework of Reference is a document that "provides a basis for the mutual recognition of language qualifications, thus facilitating educational and occupational mobility. It is increasingly used in the reform of national curricula and by international consortia for the comparison of language certificates" (http://www.coe.int/T/DG4/Linguistic/CADRE_EN.asp)
The CEFR divides the learning process into six leves: A1, A2, B1, B2, C1, C2
Basic User = A1 and A2
Independent User = B1 and B2
Proficient User = C1 and C2
If you would like to know how much English "you know" and where you should be aiming at, I recommend that you read the interesting word or pdf documents (depending on the your mother tongue) on the link below:
http://www.coe.int/T/DG4/Portfolio/?L=E&M=/main_pages/levels.html