Rental property calculator that includes initial equity???

[Carol Burns]

Hello all!  Are there calculators out there that will consider original equity at purchase.  For example, if I pay 80k for a house worth 100k, then I have an initial equity of 20k.  The calculators I've looked at just ask for purchase price.  No place to plug in present day value.  So I'm assuming all equity numbers through the years would not be correct. If I put in 5 percent per year increase in value, then it would only add 5 percent to 80k, not 100k.  I think that is correct.   Any info greatly appreciated!