Mortgage Calculator

First Look at the HP 12C Platinum

This is a first look at the HP 12C, HP’s premier financial calculator. The HP 12C is a true RPN calculator, in this video we look briefly at RPN and solve a simple financial problem.

The 12C was part of a project code named Voyager, after the 1977 NASA mission to send an unmanned probe to study the Outer Solar System. The 12C was first released in 1981 and enjoyed at least 8 revisions, the last major revision being 2015, making it the longest lived HP product and it’s best selling.

It has become the de facto financial calculator for professionals, from insurance to real estate, due to it’s simple to use financial functions and small form factor. Like other HP calculators of the time it is a true RPN calculator.

In normal calculations the operator (+-/x) is placed between operands, such as 2+2=. This is also known as infix notation. A polish logician invented Polish notation, where the operator is places before the operands: +2,2=. This is also known as prefixed notation. Reverse Polish Notation (RPN), or postfix notation, places the operator after the operands, 2,2+ RPN was designed to reduce the computer memory and processor demands while processing mathematical expressions. During the 1970s and 1980s most, if not all, HP calculators used RPN as the primary method of entry and can still be found on the flagship of the HP calculator line, the HP Prime.

Problem used in video: we are going to inverts £1000 for five years at a rate of 5%. How much will our investment be worth after the 5 years? (Solution: £1276.28)



  1. Hello I am working on calculating the amount someone would offer to buy out of a lease
    I used the following formula but I am not coming up with an answer that would make sense.
    r x t
    .08 ENTER 1 = .08
    .08 g [1/x] = 1.08
    ENTER 10,500 X
    Is that the amount you would reduce from the yearly payments due if you multiplied $10,500×12

  2. Thank you


Leave a Reply