I am a single man earning 26K take home. For a few years now I have used a simple spreadsheet for budgeting on a month by month basis as this is my pay frequency. I am looking at moving shortly so I wanted to get a better understanding of my financial situation & what I could afford for rent. It was suggested that I should do a yearly budget spreadsheet & include all possible outgoings or worse case scenarios. Previously I never included for things such as car repair bills, clothing, holidays etc etc. Because of this I would have months where it appeared that I had a few hundred pounds to spare so I would treat myself then find in a few months later I was broke when I got paid due to things that I had not accounted for. So, this brings me to my question. What is the best way of making a spreadsheet that will give me a better understanding of my finances? I was thinking that I need a column that totalled up my standard outgoings that I must pay each month such as rent, utility bills, food, fuel etc then another column with possible eventualities like car repairs, Christmas presents, holiday, clothing, eating out etc then minus one from the other & divide by 12 to give me an approximate amount of money that I should put aside each month to cover all eventualities obviously this would be approximate. Then these two columns added together then taken away from my yearly income divided by 12 would give me an amount of money per month that is truly my money to try & save or spend if need be. Does this sound like the correct approach?

When I did this I was shocked to see that I am only left with £170 per month of truly spare money for myself. Although, I have factored in a car loan repayment just because at some point my car will need replacing & if I have not saved up enough money by then then a loan would be my only possibility.

Any advice please?