Choosing The Best FE Exam Calculator: 2025 Update

There are many ways to prepare for the FE exam, but we are going to focus on just one: your calculator strategy. Calculators are obviously an important part of the FE exam and make a big difference in the time spent per question.

Read on for the ways to get the most out of your calculator for this exam.
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🔑  Key Takeaways

• Your calculator is one of the most important tools available to you during the FE exam.

• These are 3 calculators to choose from: FX-115 ES Plus, TI-36X Pro, HP 35S. Older models exists, but aren't readily available in stores.

• All the calculator options handle matrix operations, linear systems of equations, interpolation, and numerically solve definite derivatives and integrals.
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• The choice of calculator isn't as important as knowing your calculator well.  ​

• Acquire an approved calculator early in your preparation process and practice with that calculator to build your skills and speed.

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FE Exam calculator

These are the 3 models that are still readily available, if you happen to have an older model, then I suspect you're fully versed in the model and I would stick with it. If you would like to know more, and better yet, how to use that calculator to pass the FE Exam, then read on.

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If you're in preparation mode, see the growing collection FE Exam Prep Free Courses and the collection FE Practice Exams.

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NCEES approved calculators

​​NCEES publishes a list of acceptable calculators, and for 2024 it looks like this:

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The best FE Exam calculators are:

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1. Casio FX-115

You can use any of the FX-115 models, that means any FX-115 including the MS, MS Plus, MS SR, ES, and the ES Plus.

There are many models, but you'll have trouble finding a model apart from the ES Plus. So it's not worth discussing the other models, as the ES Plus has a far better screen than the older MS models.  

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2. Texas Instruments TI-30X

You can choose between the TI-30X and the TI-36X, including many versions like the A, A-SE IIB, IIS Pro, etc.  

Both of these calculators are still available in the market. The 36X is a little more money because it has a much better display screen.

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‍Update: the TI-30XS is available as a digital calculator on the NCEES exam interface.

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3. Hewlett Packard HP 35S

The two Hewlett Packard choices include the HP 33S and the HP 35S.

The 35S has replaced the 33S, and you'll have a tough time even finding a 33S. They've upgraded it for a reason. It's just better than the older 33S launched in 2003.

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Update: You'll have a hard time finding the HP 35S as it too is discontinued.

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Note: both of these calculators use the RPN system (Reverse Polar Notation ... 5 enter, 5 +, equals 10), and it takes a bit to get used to. I like it better, but there is a learning curve, so if you're short of time, do not go this route.

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Updates:
You can now change both of these calculators to a standard Algebraic Notation like a standard calculator.
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There are HP calculators available on the internet that have formulas pre-loaded for the FE exam and PE exam.

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Know your scientific calculator

It's difficult to pick a clear winner, but here's a decision matrix to help you decide. But all these options are great, they all handle:

• matrix operations
• linear systems of equations
• interpolation
• numerically solve definite derivatives and integrals

So the real power is knowing how to do this with your choice of calculator.  

It's also important to know what marks you'll need to pass the exam: FE Exam Passing Score.

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FX-115 ES Plus calculator tutorials

Logarithmic Equation |  WATCH VIDEO

A useful calculator tutorial outlining how to solve logarithmic equations for unknown variables. This is done quickly using the solve function for the Casio calculator.

Solving Permutations | WATCH VIDEO

In the word “Calculator”, how many ten letter arrangements are possible, with no repetition, if the first letter is a vowel. Be careful as there are two vowels.

Solving Matrices | WATCH VIDEO

This is a longer 10-minute video that solves addition, subtraction, multiplication, and division operations with matrices. Once you store a matrix, it's critical to be able to recall it and perform another operation. A great video.

Complex Numbers | WATCH VIDEO

How to simply complex number expressions and perform basic functions with complex numbers using the fx-115. Be sure your calculator is in complex mode.

Definite Integrals | WATCH VIDEO

This video is another long one that we split into two parts. It involves solving definite integrals, and this material will be in your exam, and it's good to know how to use the calculator to do the work for you.

Definite Derivatives | WATCH VIDEO

This is the second part of the video that works with solving definite integrals. Definite, meaning we are solving the equation for certain numbers, rather than solving generally. Don't wait until during the exam to become familiar with this great feature of the calculator.  

Video sources include EquaterTV YouTube Channel, and Joel Erway's YouTube Channel.

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HP-35S Calculator Tutorials

HP released a calculator simulator that can walk you through:

• solving vector equations and the corresponding geometry
• solving matrix determinants and basic operations with matrices
• the time value of money and interest calculations
• beam stresses
• solving a system of linear equations
• a series of electricity examples​

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FE Exam calculator tips

Start using your calculator today.

Your first step will be to get one of these calculators well before you take the exam. When you are studying for the FE exam, whether it’s working example problems or taking a practice exam, you should always practice with the same calculator your plan to use on the exam.

Knowing the layout of the buttons can save you time and errors in entering formulas. While some problems may be of the “plug and chug” variety, you still have to plug in all those numbers. Even a minor typo can cost you precious time.

By practicing this way, you build up both skills and speed, giving you an advantage on exam day. Remember – every few seconds you save is time you can direct towards the most difficult problems.


Investigate The Power Of Your Calculator.

Most of us barely scratch the surface of what our calculators are capable of, even with the simpler scientific calculators. Take some time to get out your user manual and find out what you can do. If you don’t have a user manual, don’t worry: you can find them on the web fairly easily.

It won’t take you very long to skim through the topics to find functions and commands that will help speed up your problem solving. Remember: the goal is to figure out how to get the most out of it for the FE exam.

If you decide you want to use a specialized command or function, don’t wait until the night before the test to try it out. Let’s say you are going to use an integration function on your calculator. Your first step should be to take a moment to look that function up in your user manual. Next, try using it with some problems you already know the answer to in order to make sure you are using it correctly. It would be a shame to use the right function to get the right answer to the wrong problem on the FE exam!

If you are new to the particular calculator you are going to use, make sure you can perform relatively simple calculations involving things like exponentials, logs, and memory. I once had a friend purchase a brand new calculator right before an exam, only to fail because he wasn’t using it correctly.​

Finally, make sure you have fresh batteries for the HP the day of the exam (unless you are using solar models). If you leave batteries in it for months at a time, the batteries will drain.

Your calculator is one of the most important tools you have available to you during the FE exam. Don’t forget that buying the right calculator, and using it when you study for the FE exam has the potential to help you do even better. Take the time to investigate what it can do, make sure you are using any new functions or commands correctly, and protect it from damage. Your calculator can either be your best friend of your most insidious enemy – the choice is yours.

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NCEES calculator (in-exam)

There is also a calculator built in for the CBT system for the FE Exam as you can see below. This isn't a great solution as most people are far faster on a conventional calculator and we know time is of the essence in this exam.  

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