You can make utilities for yourself where you can put all your calculations and worksheets. This will reduce repetitive work to a great extent and help you save time for some other productive and constructive work. Apart from them, there are a countless number of other ways to use spreadsheet such as planning your tax, investment, cash flows, managing phone numbers and contact details and the like.
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.