Personally, I have never found percentage guidelines that helpful, since they vary depending on the persons salary. The important thing is to work out a definitive list of outgoings in a month and compare to your incoming salary. You need to build in outgoings for all bills, insurance, internet access, food, travel, contingencies for house repairs & car repairs, general savings, etc. At the end of that process if incoming > outgoing then it works. (However you also need to calculate a 'what if' plan, what if your incoming drastically changed, in a worse case scenario went to zero? Unless you know how you can pay everything off for a year then your outgoings could be too high.)