It’s important to do your sums before buying an investment property. This calculator will enable you to do a rough feasibility study as a guide.
Keep in mind that non-cash items like depreciation and building allowance give you a tax deduction, and so put money in your pocket, but do not require you to expend any cash.
The calculator enables you to work out how much you need to find in the way of those non-cash deductions for the project to break even on a cash basis.
Keep in mind that the higher your tax bracket the more a tax deduction is worth. It may be worthwhile reading Winning Property Tax Strategies written by Julia Hartman and myself.