Part of the fundamental financial analysis of any company, investment security, or business project entails the computation of cash flows. This is typically done in a cash flow template Excel spreadsheet which is pre_built for the purpose. The reason for this is that this type of template is not a simple calculator you build on the fly with little effort. It requires a lot of thinking, organizing the spreadsheets and formulas, and some planning about how to model cash in and cash out for each potential investment. In other words, there is no cookie cutter approach because each potential investment has different profit and loss drivers.
You can use templates to help you get healthier. There are a couple of designs for a diet and exercise diaries and grocery lists. You can even create a household budget or a household chore list. Figuring out how long it will take you to pay of your home loan can be done using a Microsoft Word template. Seems like there might be template for every aspect of life.