To keep our financial, investment, tax, health, birthdays information and the like. We can use it for simple as well as specialized calculations. Like, comparing cost and returns of various loan, investment and insurance options available in the market.
The great thing about personal budgeting spreadsheets is they can easily be modified to fit your budget. You can enter the exact categories you use monthly for your income and your expenses. These categories can be really detailed such as having individual credit cards listed by name or they can be broad such as having one group named credit cards for all your credit card bills.