I've been a civil/structural engineer for 20 years now. My HP 48GX has recently done its last calculation. So I looked for a replacement and it seems that the market for scientific/graphing calculators has changed.

My question: Could it be that smartphones are replacing calculators in the engineering world and all one needs to do is buy an "graphing calculator" app?

(I am not referring to the open sourced HP48 app)

  • $\begingroup$ They definitely still sell a lot of the old graphing calculators (I've still seen TI-84s selling for like $150 CDN). That said, now that you mention it, I'm not sure why there would be much of a market for them now. A context where you couldn't use them would be in a school exam, you also might have some issues if any features are tied to the Internet and you lose signal. Good question though, I'm curious about the usefulness of calculators when everyone carries around computers now. $\endgroup$ – JMac Feb 23 '17 at 10:52
  • $\begingroup$ @JMac on the contrary, school exams, and math classes in general are where students not only are encouraged to use scientific graphing calculators in many cases, it's required. My son, a sophomore in high school is using a TI-NSPIRE CX, provided by the school to use in class and on exams for his math classes. $\endgroup$ – DLS3141 Feb 23 '17 at 15:20
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    $\begingroup$ This question is pretty much just asking for a list of opinions. The answer is that you should use whatever you are comfortable with. Nothing has changed about engineering that makes a slide rule unacceptable. It is solely down to whatever you are comfortable with and proficient at using. For quick and simple calculations, there is no difference between paper and pencil and a computer simulation. $\endgroup$ – hazzey Feb 23 '17 at 15:23
  • $\begingroup$ @DLS3141 Sorry, there was ambiguity in my wording. I meant exams were a context where you couldn't use smartphones, not graphing calculators. Generally the rule for tests where graphing calculators are allowed is that the device can't connect to the internet. I will add that often once you get to university some professors will limit calculators to 2-line displays so that students are unable to plot graphs with the calculator instead of by hand. It definitely depends on the context of what you are teaching. $\endgroup$ – JMac Feb 23 '17 at 15:35
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    $\begingroup$ @DLS3141 in a public classroom setting that's all well and good, but universities usually don't pay for the graphing calculators, so you couldn't really ensure a system like that would work. The communication features are nifty though. We had docking stations in high school for TI-83+'s that had a feature like that. We took interactive tests, it was cool. $\endgroup$ – JMac Feb 23 '17 at 20:15

When I'm at my desk I have a desktop computer connected to the internet in front of me and a smartphone with a scientific calculator app installed in my pocket.

If I need to do some quick calculations I will still reach for my old calculator that I've had for around 24 years now (it still has the sticker on the back saying it's OK to use in university exams).

I find the physical keys quicker and less error prone to use and it just feels more natural. And while the actual processing speed is a tiny fraction of the other devices I have available it's good enough for the job and the battery life is far better (So far it's averaging 1 AAA every 10 years.)

If it died I'd certainly look for a replacement but I suspect the market is significantly smaller these days, if I didn't use it regularly I'd probably make do with the smart phone app myself.


IMHO an app such as wolfram alpha can easily replace a calculator. Some additional advantages:

  1. Possibility of integration with other apps. E.g. Save results and send them to your computer for further analysis.
  2. Extended functionality, such as 3d plotting.
  3. you do not need an extra device, since you always have your phone with you.

Some reasons to stay using a calculator:

  1. It is faster to use. The HMI is tailor made for entering equations.
  2. You do not need an internet connection.
  3. Battery life is better.
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    $\begingroup$ And schools like to use calculators instead of mobile phones / computers to avoid communication (though avoiding communication on school computers is also possible). $\endgroup$ – Karlo Feb 23 '17 at 11:34
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    $\begingroup$ @Karlo In my experience some courses aren't even allowing graphing calculators for exams. Often you're expected to have basic scientific functions and everything else you can work out by hand (and knowing what a graph should approximately look like without a calculator is a pretty useful skill). $\endgroup$ – JMac Feb 23 '17 at 11:43
  • $\begingroup$ @JMac Indeed, some courses are with (graphical) calculators while others are by hand, possibly with some tables. $\endgroup$ – Karlo Feb 23 '17 at 11:51

A calculator, today, is more about giving school exams a sandbox than about calculating. Any general purpose computer can do the same with fewer resrictions, including your phone. When you are sitting on your desktop you should be using the desktop.

While its true that a calculator can have a better tactile user interface than your phone. Its still a marginal benefit when your phone can integrate into all your systems better more easily. You can even find, FEM, statics and other specialized apps. Even when you can not, you can network with your phone and use matlab, mathematica, ansys, abaqus... that is on your work computer.

This means you can save calculations for reuse, for documentation nicely typeset etc. You use less time switching between systems for less transfer of errors.

So the answer to the question is: No. There is only a marginal use for a calculator, many reach for a calculator out of habit more than benefit.


The market has definitely changed: HP only has 8 calculators on their web site, and the hp50g (the last descendant of the hp48 series - or of the hp28 series if you look even farther back) was discontinued in 2015.

all one needs to do is buy an "graphing calculator" app?

I have and use an hp48 emulator on my phone, but it's not the same as a real 48, so I have two of them kicking around at all times - one mostly at the office, one at home. I have an hp48sx that I bought in college, so it's more than 20 years old, and a 48G I bought off of craigslist about 5 years ago.

Even on a smartphone with a large screen, the interface on a real hp48 is better - the positive feel to button presses and the lack of swiping issues are the two things I find the most beneficial about the real calculator. Just turning it on is easier on the calculator - push the on button, no unlocking, swiping to the right screen, etc.

Even for a simple 4-function calculator, I'd rather use an old hp than a phone. I have a bunch of old calculators and at different times I've used an hp34c or an hp12c - even with LEDs, they last a long time on a set of AAs. (I'd fire up my 28S or 41CV except that N cell batteries are a pain.)


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