Well, yes and no. In the sense of yes, you can include your existing properties into the calculator. You can input all the rental related information, income information, expenses, and tax information etc on a yearly basis. However, the Ultimate property investment calculator is an investment property analysis program not an accountancy program so you should not expect it can do a good work on what it is not designed for.
As a bonus for my clients, I provide an Investment Property Management Spreadsheet (worth $69.99) for free. This spreadsheet is specifically designed for the purpose of keeping track of your investments (rental expenses, income, etc) so that at the end of the year you can simply print off a report for your accountant. Moreover, this spreadsheet estimates the tax refunds you can possibly get from ATO, isn’t it handy? You can keep track of up to 12 properties.
The Investment Property Management Spreadsheet has two versions. One is using Excel macros to automatically fill in the daily rental income information so you get an accurate monthly income – you can also input everything manually.
BTW, do I mention that you receive free update to this tool as well?