How much extra curricular information should I include?

The personal statement is primarily used to show off your interest in your chosen subject. Therefore the majority of it should contain information relevant to your studies, or to extra involvement in your subject. However, many people choose to include some information about their extra curricular hobbies and activities in their personal statement. This is perfectly fine, and many universities use this to get a sense of you being a more well rounded person. However, universities like Oxford and Cambridge tend to ignore this information, and so it is recommendable that you keep it to a minimum if applying to these universities so as to not use up space which could be used to sell yourself to them! Similarly, the type of extra curricular information you should include will be different depending on your subject or university - sports orientated universities might be more interested in the sports you play, whilst your achievements working for a charity may be more relevant to another university.