It depends on what the subjects are and how well they complement each other. I've done four A-Levels successfully and it is absolutely possible (and definitely not a waste of time), without detracting from the time you have for extra- or super-curricular activities and for doing things you enjoy. Doing four also gives you greater flexibility when applying for university courses, because so many university courses require specific subjects - having four opens more doors. If you're expecting to achieve mainly 8s and 9s in your GCSEs, doing four A-Levels - or at least starting off that way - could be the best choice for you. In terms of the jump from GCSE to A-Level, some people do struggle with it and the best way to get on top of it is to really focus on exam technique when you revise for the GCSEs you will be doing at A-Level. When you get to Year 12, you will only be doing 4 subjects rather than 9 - 10, so you will have a lot more time to concentrate on each.