The books I've read refer to the Cash on Cash return as a snapshot in time. It is the return on your cash invested in year 1 of owning the property. It has nothing to do with the possible appreciation of the property, the mortgage reduction or the tax savings. How do you calculate your Cash on Cash return after year 1? Well, that seems a little tricky, as in year 2 your property appreciated and your mortgage balance was reduced. That is real money that you just made in addition to the cash received. How would you account for that money mathematically? Which formula do you use? The Cash on Cash return formula is no longer appropriate, as that only accounts for your initial down payment and the cash flow received. I believe what @Llewelyn A. is explaining is this very concept and one I don't hear a lot of talk about, which is your total Rate of Return. As I have come to understand it(correct me if I'm wrong), I refer to it as the Internal Rate of Return(IRR). The IRR will take into account the cashflow, appreciation and mortgage reduction for a property. However, the timing of these cash amounts are important as well, which the IRR takes into account.