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.
One of the first things to consider is what kind of data you have to work with in your cash flow template Excel spreadsheet. Ideally, you're looking for accurate monthly data including income statement items like revenue and operating expenses and balance sheet items like equipment purchases and cash from financing activities. If you have a longer time frame you can go with quarterly periods, but annual tends to be too long. After all, how can you predict what is going to happen beyond 5 years with any accuracy unless you're valuing an annuity?