12C Financial Calculator – 120+ Functions: TVM, NPV, IRR, Amortization, Bond Calculations, Programmable Keys (HP)

I have been using the HP 12C for over 20 years, and its enduring quality is absolutely legendary—my original units are still working perfectly today. This calculator is a durable, reliable workhorse that covers all the critical functions needed for finance: Time Value of Money (TVM), NPV, IRR, Amortization, and Bond Calculations. Comparing it to modern devices, it's interesting to note how much faster technology has become. On older HP 12C models, running complex calculations like the Internal Rate of Return (IRR) would often display the "running" indicator for a noticeable period. The newer calculators are so incredibly fast that this indicator no longer appears, completing the task almost instantaneously—a small detail that highlights the HP 12C's incredible tenure in the market. The most important thing to note before purchasing is the requirement to use Reverse Polish Notation (RPN). This is a different input method than the standard algebraic method you might be used to. Instead of typing "2 + 2 =", you input the numbers first and then the operation: "2 [ENTER] 2 [+]." There is a learning curve, but once mastered, RPN is far more efficient and reduces the chance of input errors. It’s what makes the 12C a favorite among financial professionals. This is a fantastic, indispensable tool that I highly recommend for anyone serious about personal finance or real estate.

The old and useful HP calculator that I keep with me everywhere. No issues and great delivery.

There are many GBs of web pages devoted to the HP12c. Suffice it to say this is a brilliant financial calculator and I recommend it to anyone working in finance or banking. Yes, the spreadsheet is much more powerful and thanks to our phones, very portable. But this is designed to fit in your short pocket. The level of design is immense. The HP 12c has remained in production since 1981 and the user interface is unchanged. However, this version of the HP12c is super fast (it unofficially referred to as the HP12C+). The original physical technical architecture no longer exists so the software runs on an ARM chip. The batteries may not last as long (we are talking months… not daily recharging!) but I will take the speed any day. These calculators do not come with a manual but you can download the VERY comprehensive manual from the web. There is also an advanced manual called the solutions manual. These books are mini finance courses which introduce you to the HP12c. The calculator uses RPN. If you have used it, you will love it. If not, it is odd… but no one will ever take your calculator at a meeting. You need to learn RPN (there are videos to explain) but if you work through the instructions you will do that in no time… the trouble will be going back (it is faster than conventional calculations). You can write simple keystroke programmes for this calculator. This can be useful but in all of my years of using the HP12C, I have not written any elaborate programmes. These calculators can be “flashed” with a special cable (there is a socket in the battery compartment). I have not done this so I cannot comment on the process. The build quality is very good. These calculators are made in the Philippines. For this price, the HP12C is amazing value.

I've purchased several of these Financial Calculators over the years. We use them at work and they are great!

Ordered from a different seller and it was clearly a knockoff. Keys would double or triple enter. This on works perfect and original packaging from what I can tell.

As a mortgage loan officer, I work with numbers all the time. I love the way this calculator works. Once you get used to it, you never wanna go back to old school calculators. This is my third one.

Updated, HP12c calculator, the classic comes with batteries pre installed! My old one was 40 years old, so one to replace. This one did not disappoint!

Excellent, great replacement for my old one from 1990. UPDATE Oct 2025, this works well some/most of the time but it sometimes skips a number entry while giving the feel it’s been entered, eg adding up a bunch of numbers. It has thrown me off a few times and that’s been frustrating. I recommend only using it on a very hard surface and paying close attention to numerical entries. Double check your computations. Bummer it’s brand new and not reliable. My HP12 from late 1980s is better, but I needed a second one and didn’t want to chance buying used.