I've been playing with amortization calculators and have seen you can pay off 1/3 of the mortgage and reduce 2/3 of the duration.

However, from my experience in Europe, particularly in the Netherlands and Spain, calculations still play a big role in ensuring the profitability of a flipping or rental project.

I think your best approach is to pretend you are the investor yourself, calculate build cost (mortgage with interest) + Maint / cap expenses/ management fees according to your zoning and then compare that to the average rent in that neighborhood.

Hi everyone, joined BP last year for all the freebee calculators and finding myself a bit over my head and in need of some advice...Have a commercial property bought on land contract, 0 down, 5%, amoritized over 30 years with 6 year balloon for 120k last year.

When you looked at the numbers on the top 3, they all had good cash flow and great appreciation (the numbers were calculated as though no equity had been extracted). 

I am assuming that these expenses should be factored into your budget prior to calculating your cash flow.

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

Quote from @Levi Perl: Hi,Curious if anyone has what to say in terms of how to calculate which one is more worth it: to cash out refi on a Long term rental now at 70% LTV, and walk away with X amount of positive cash AFTER paying all debt, (X is a positive number and significant amount for me), which will allow me to potential get another long term rental and grow portfolio faster, or wait 4 months and cash out 80% LTV, giving me DOUBLE than X. 

You said "don't do it for the money," but I'm sure money calculations were part of convincing you this would be a reasonable way to spend your time and money.

Make sure to calculate the difference between the blended rate and an entirely new first lien position.