My trusty HP 15C Engineering calculator is still with me after 23 years. Purchased my freshman year in Engineering school, it has been abused in every way, including a trip to the bottom of my parents swimming pool. So when I was in need of a new calculator with financial functions on it I went straight to the HP website.

CCIM pushes the HP 10BII. This is the "official" calculator they want everyone to use in their classes and on there tests. So I bought this model first.




I will admit it is a nice calculator. The financial functions work very well. While not intuitive at first, you will find that as you use the calculator, the functions work in a way that streamlines your key strokes. Because this is a "standard" calculator (not RPN which I will get to in a minute) it is easy for everyone to use.

Unfortunately, the model I bought was not well made and the keys had a tendency to stick.

As I mentioned, I have had a HP 15C for ever and am fully accustomed to the backward and different approach this tool uses for entering calculations. This approach is called Reverse Polish Notation (RPN for short) and is characterized by the absence of an "=" key on the calculator.

The HP 12C is almost identical to the HP 15C in appearance and adds Financial functions at the expense of some Engineering functions.

I purchased an HP 12C and have not looked back. While not the same quality as my 15C (HP now makes their calculators in China. The older ones were made here in the states) it has the same wonderful functionality.


RPN (explained well by Wikipedia, see link at bottom of article) is a tremendous boon when doing multiple calculations and in cases where the results of the previous calculations are a component of your current calculation. Once you are accomplished with RPN you will be able to work relatively complex financial calculations without having to write down answers and numbers along the way. The RPN scheme effectively stores and tracks these bits of information as you go.

Both of these calculators come with very good instruction manuals which have plenty of examples of Real Estate calculations. Read the table of contents so you know all of the things these calculators are capable of and then work the real estate and Loan examples and you will be ready to any basic mortgage calculation, determine Cap Rates, Cash on Cash, and Debt Coverage Ratios.

One caveat - Once you have converted yourself to the RPN approach you will never go back.

Additional Bonus - No one ever borrows your calculator once they notice it does not have an "equals" key.


For more about RPN go to: en.wikipedia.org/wiki/Reverse_polish_notation
For more about the HP 10BII and HP 12C go to: http://h10010.www1.hp.com/wwpc/pscmisc/vac/us/en/sm/calculators/index.html