Calculator Selection Guide

Why a good calculator nowadays?

We acknowledge that Excel is better than a calculator for most things (though not all), but there are many occasions where you cannot have Excel, or it takes a long time to start up (computer included), or it is overkill. In examinations, in business meetings, during a presentation, the only available solution is a calculator. And then, you'd better have a powerful, reliable, quality calculator.

What are the key features for a calculator?


  • Functions – the more functions a calculator has, the more difficult will be to access them (and the more memory -your own memory!- you need to use it). The menu-driven 20b and 30b take more keystrokes to access a given function than the 1-function-per-key 12c, but also more than the menu-driven 17bII (which for me is the top calculator in ease of use)
  • Programmability. This feature puts off many people, and it should not. Many HP calculators use keystroke programming – which in its simplest form is akin of recording the steps you usually do when solving a problem. Other calculators are not programmable – like the 10b and 20b; and finally other calculators use the Solver which helps to automate many frequent tasks. The Solver facility can do many things that a normal program can't.
  • Keyboard feel: odd as it may seem, some calculators give real pleasure when keying numbers, while others are a real pain. Key-pressed feedback is one element, but not the only one. HP calculators have been excellent in this regard, with a few exceptions. The slanted, hinged key with 2 functions on it is an HP trademark, but it is not used across the whole line.
  • Screen quality. The current HP screens are excellent, but there have been occasions in the past where this was not the case (HP 48GX, for example). I prefer the HP 50g, HP 12c and HP 17bII over the others.

Financial, Scientific or Graphical?

As an engineer with 20 years’ experience, I have never used complex numbers or hyperbolic functions in my job. I have used trigonometric, logarithmic and exponential functions quite often, and –maybe surprisingly- I have used quite often the Time Value of Money equations, as well as Net Present Value and IRR formulae. Please do the same reflection for yourself. Picture the things you do most often in Excel. List them down and compare performances. We have tried as well to see the calc most suited to you according to your personal situation in the enclosed file.

Graphical Calculators

As a general guide, the graphical calculators are the most complete – and you can program them in the areas not covered. In many cases, you can download programs other people have written, and transfer them to the calculator through COM or USB ports, or even SD cards. This implies, of course, that you are able to program, or expert in transferring information from a computing device to another (this may be the case if you are a science student or engineer). For high school or college, this is the calculator to have.

However, these calculators are big and complex. The programming paradigm (RPL) is elegant, but it is yet another programming language you need to master[1]. And you need to find where the function you need is. On the other hand, this is not the calculator you want to take in your jacket with you. You need to know as well that there are emulators that run in Windows (you can find some in our software area – a good way to try before buying)

Up to now, the best calculator produced by HP was the HP50g. Programmable in HP's trademark RPL, with good readability graphical screen, extremely fast, robust and with an enormous library of programs that can be downloaded fo free in

Recently, HP has issued 2 calculators, based on a different programming paradigm. 

The first is the HP 39gII. Despite its name, it has nothing to do with the original HP39gs model. It is extremely fast, and programmable in a kid of Basic, proprietary to HP, and quite flexible. It has a much better screen with higher resulution and 16 shades of grey. 

This September, HP has just introduced the HP Prime. It is aimed to the educational market. The array of features included make it ideal for the classroom, and even more for the whole classroom. it has an exam mode, whereby the teacher can deactivate from his desk, via checkboxes in his computer, specific features in the whole classroom calculators, so that they can perform the test unassisted. The teacher can upload exercices and lessons to the students' calculators, so that they can work at their own rythm.

In most cases, you will be better off with either a scientific calculator (and here my choice is the HP-35 as current calculator, or a 42s or 15c (please see the Classic Calculator area on our website)), or with a financial calculator.

(A comment here: for many people, the best scientific calculators ever were the HP-15c and the HP 42s. So much so that you can find them in Ebay for over 250 € for well maintained units. Both fit in your jacket inner pocket, both are keystroke programmable, and you can port the financial features through available programs to both. I do not think you will ever see the HP 42s back in production – but stay tuned here regarding the HP 15c !!)

I am sure there will be numerous apps that can be aimed for professional use. In fact, the machine comes with a powerful financial solver, as well as general solvers for multiple applications.

Financial Calculators

Financial calculators are sometimes derided by technical or non-financial people, but I have found in my professional life that you can do most of your current tasks with one of them.

If you look for portability, then the HP12c and HP12c platinum are the ones you need. They have been around since 1981 for the plain 12c, and since 2001 for the Platinum. They have the basic functions for a financial calculator, in a very cleverly laid out keyboard, and this is all you need to challenge anyone making a presentation in a boardroom. Both have IRR, NPV, Time value of Money, and basic date and statistical functions. In the back of the calculator you have a simple guide that is enough for most tasks.

The basic difference between both are:

  • The HP 12c platinum has more memory – 400 programming steps instead of 99. This is irrelevant for the typical customer – you will not use them.
  • The HP12c platinum has a backspace key. With the plain 12c, you need to clear the screen (CLX) if you miss a keystroke, and then start over. This is an important advantage of the Platinum
  • The HP 12c platinum has an algebraic entry mode. By all means, learn RPN – you will thank us for the hint all your life.
  • The HP 12c is silver versus the more classy gold.
  • Now, there are no differences in speed. The new ARM-based processors are 150 times faster than the original 1981 HP12c, and some 25 times faster than the best previous Platinum. (with us, you will be guaranteed to have the ARM processor – we know our business)
  • The current HP12c comes in 2 different versions, produced by 2 different factories: Kimpo and Invertec. Apart from their code in the back and the serial number (CNA for Kimpo and CY for Invertec at the beginning of the serial number), they can be told apart by the different size of the % sign, and the slightly thinner letter font. It is generally accepted that the better ones come from Kimpo. There is no way to know in advance which one you are going to receive when you order one (neither is it possible for us, since both are the same product code and the distributors will not separate them
  • Recently, with the 30th anniversary of the introduction of the HP12c, HP has issued the HP12c Anniversary. For all practical purposes, is an ARM HP12c, with better packaging and slightly better pouch than the original, sporting as well the "Anniversary Edition" label on the golden bezel.

The new 20b and 30b are based as well on ARN processors. The 30b is programmable and has a much better key feel than the 20b. The look is classier as well. Both of them are customizable into the wp34s, and we can do it for you.

When it comes to the 10bII - there are two models you can find:

  • the classic 10bII - stay away. Not RPN and purely financial features. Nothing special
  • the new 10bII+ - a winner! You can recognise it for having all the keys with blue markings: it has all scientific functions as well! It sports also a break-even calculation tool, several statistic tests and distributions, etc. The one to go if you do not want to navigate menus. Based on the powerful ATMEL processor, it is as well blazingly fast.

The Calculator as a Gift

HP is different from other calculator makers in that some HP calcs do really look classy and professional. Take the HP 17bII with its silver livery – or the 12c or 12c Platinum. It is the ideal gift for the graduating professional, or for the typical 10- or 25-years anniversary in the company. It is a good year-end business gift as well, for appreciated business relations. We can provide as well nice gift packaging - please contact us for details for wither one-off or series gifts.

Later in 2011, HP issued the HP12c Anniversary Edition, in a beautiful box - ideal for a gift to any financial person. It only comes in English

And starting 2012 (in Europe), HP issued the much awaited reedition of the HP15c scientific calculator, one of the peaks of the long HP calculator history. This calculator comes in a very nice box, as opposed to the usual blisters, and comes with a full facsimile of the original manuals (probably the best ever made by HP or any other maker for that matter). It only comes in English as well. Based on the ARM platform, it is 100 times faster than the original. For me, the ultimate gift for any engineer that does not have a 48-famiy calculator.

[1] The HP 50g can be programmed in several languages – C being the most desirable for its customers. Check the HPGCC initiative.