I have an ARM product that I want to calculate (NOT VERIFY) the APR - I need a tool to plug in the various components to get to the APR -- is there a free tool out there.

Do you mean a loan amortization tool? That's the only tool I can think of that can't be accomplished through the use of APRWIN (which is free). I don't know of a free reliable loan amort. tool. You need to make sure that it handles all the parameters, like 30/360 versus actual/actual or actual/365 or 366. This all depends on your note and processing systems.

Not necessarily - I don't need the full amortization table -I need a reliable tool where I plug the loan amount, index, margin, rate, etc. and get the APR.

Try Execamort from Electrosonics in Fraser, MI. It is an old DOS software program that will run under Windows.

I just found this ARM calculator
http://nt.mortgage101.com/partner-scripts/1144.asp?p=mtg101&pw=760

Looks like it covers some of the bases, but what about:
- odd days
- PMI (with mandatory termination at 78% LTV)
- Rate caps & ceilings

The APRs are also inaccurate. You get what you pay for.