There are at least a couple major problems with this method. First, it's pretty easy to overlook quite a few expenses. Things like that daily stop at the coffee shop, or the cost of a car registration that happens only once a year.
Budgeting Worksheet: Compare your Monthly Spend to a Standard Guideline _ Once you put your numbers in, how do you compare to the national average or some other standard guideline? The budgeting worksheet should give you some idea of how you compare in each of the above categories. Then you can make some decisions if you're over or under spending in some areas. The beauty of using worksheets is not only to see where your money is going but to see how you compare to a standard guideline.