Which calculator should you use?
If you are looking at a specific property, start with the rental property calculator: it combines financing, operating costs and returns in one analysis you can save and compare. The single-metric tools are for when you already have the inputs and need one number. The rent and tenant tools cover the day-to-day questions that come up once you own the property, and the tax tools estimate depreciation while you hold it and the tax when you sell.
Every calculator shows its formula and assumptions. Read the methodology for the full detail.