How much spending money you should have each month depends on you. However, to determine this amount, you need to get a sense of how much you are spending per month compared to what you earn. This way, you can set spending limits. The first step is to take a look at mandatory expenses, then add them up and subtract the total from your income. The amount you have left is what you can budget for discretionary expenses and savings goals. There are many different budgeting strategies you can follow to determine how much you spend each month. Generally, what you budget for expenses should not be more than your income; otherwise, you will end up in debt.