Best Calculators for the FE Exam 2026: All NCEES-Approved Models Compared

Why Your Calculator Choice Matters for the FE Exam

The Fundamentals of Engineering (FE) exam is the first step to becoming a licensed Professional Engineer (PE). With 110 questions in 5 hours and 20 minutes, you need to solve complex engineering problems across statics, dynamics, thermodynamics, fluid mechanics, engineering economics, and more — all under serious time pressure.

Unlike many professional exams that provide a built-in calculator and prohibit personal devices, NCEES requires you to bring your own approved calculator to the FE exam. Choose the wrong one, and you waste precious minutes on keystrokes that should be automatic. Choose the right one, and matrix operations, unit conversions, and equation solving become effortless.

Here is the detail that catches many candidates off guard: NCEES only allows one personal calculator in the testing room. You cannot bring a backup. However, NCEES does provide a digital TI-30XS MultiView calculator on screen during the entire exam — so you have a built-in fallback, but it lacks the advanced features (matrix operations, equation solver, numeric calculus) that make the top-tier models so valuable.

The calculator you practice with for months is the calculator you should bring to the exam. Start practicing early and make your choice count.

Complete List of NCEES-Approved Calculators

NCEES publishes an official calculator policy listing exactly which models are permitted on all NCEES exams, including the FE. Here is the complete list as of 2026:

Texas Instruments:

• TI-30Xa (including TI-30Xa Solar)
• TI-30XIIS
• TI-30XS MultiView (also provided digitally on screen)
• TI-30XB MultiView
• TI-36X Pro

Casio:

• fx-115ES Plus (including 2nd Edition)
• fx-115MS
• fx-991ES Plus
• fx-991CW
• fx-991EX (ClassWiz)

Hewlett-Packard:

• HP 33s (discontinued)
• HP 35s (discontinued)

Important: NCEES states that all models within an approved series are permitted. This means variants and regional editions (like the Casio fx-115ES Plus 2nd Edition) are allowed. However, models not on this list — including graphing calculators, CAS calculators, programmable calculators, and phone apps — are strictly prohibited.

Bottom line: Of the approved models, the two HP calculators are discontinued and increasingly hard to find new. Focus your choice on the TI and Casio models that are readily available and well-supported.

The TI-36X Pro Advantage

Before we dive into individual reviews, let's address the elephant in the room: the TI-36X Pro is the consensus number-one pick for the FE exam, recommended by approximately 80% of FE prep sources, engineering forums, and university programs.

Why has it earned this near-universal recommendation?

1. Four-line MultiView display. The TI-36X Pro shows up to four lines simultaneously, so you can see your entry, intermediate steps, and the result all at once. On a 110-question exam where you are constantly referencing previous calculations, this is a massive time saver.

2. Built-in equation solver. Enter an equation with one unknown and the calculator solves it numerically. This handles everything from simple algebra to complex engineering formulas without manual rearrangement.

3. Matrix and vector operations. The FE exam frequently tests linear algebra — solving systems of equations, determinants, and matrix multiplication. The TI-36X Pro handles up to 3x3 matrices directly, saving minutes of hand calculation per problem.

4. Numeric calculus. The calculator can perform numeric integration and differentiation. While you need to understand the underlying concepts, having the calculator verify your work or handle tedious numerical integration is invaluable.

5. Unit conversions built in. The FE exam loves unit conversion problems. The TI-36X Pro includes a comprehensive unit conversion function covering length, area, volume, temperature, speed, mass, force, energy, and more.

6. Polynomial root finder. Enter coefficients and get the roots of quadratic and cubic polynomials directly — a common need on the FE exam.

7. Every FE prep resource teaches it. PrepFE, PPI (formerly known as the Lindeburg review), Gregory Michaelson, and virtually every YouTube FE prep channel teaches keystrokes for the TI-36X Pro. When you hit a tricky calculator problem, you will always find a tutorial.

The TI-36X Pro is not the cheapest option, and it is not the most powerful in terms of raw function count. But its combination of the right features, dominant tutorial support, and proven track record on the FE exam makes it the safest choice for most candidates.

Side-by-Side Comparison

Key takeaway: The TI-36X Pro, Casio fx-115ES Plus, Casio fx-991CW, and Casio fx-991ES Plus all offer the advanced features (matrices, equation solving, numeric calculus) that FE candidates need. The TI-30XIIS is a basic scientific calculator — adequate but lacking the features that save real time on the exam.

Our Top 5 NCEES-Approved Calculators for the FE Exam

1. TI-36X Pro — Best Overall

The TI-36X Pro is the gold standard for the FE exam. It dominates engineering exam prep the way the TI BA II Plus dominates financial exam prep — not because it is the most feature-rich, but because it has the perfect balance of power, usability, and tutorial support.

Why FE candidates love it: The four-line MultiView display is genuinely transformative for an exam where you constantly reference previous calculations. You can see your entry, your previous answer, and your current calculation all at once. On a 5-hour exam with 110 questions, this eliminates countless "wait, what was that last number?" moments.

Key specs for FE:

• Four-line MultiView display
• Equation solver (numeric, one unknown)
• Matrix operations up to 3x3 (add, subtract, multiply, determinant, inverse)
• Vector operations (cross product, dot product)
• Complex number arithmetic
• Numeric integration and differentiation
• Polynomial root finder (2nd and 3rd degree)
• Comprehensive unit conversions
• Fraction/decimal toggle
• Statistics with regression analysis

Why ~80% of FE prep sources recommend it: Every major FE review course — PPI, PrepFE, School of PE — either teaches the TI-36X Pro exclusively or as the primary calculator. YouTube is filled with TI-36X Pro FE tutorials. When you search "how to solve [FE topic] on calculator," the TI-36X Pro result appears first almost every time.

Pros:

• Dominant tutorial and community support for FE exam
• Four-line display shows multiple calculations simultaneously
• Built-in equation solver, matrices, vectors, numeric calculus
• Unit conversions save time on conversion-heavy problems
• Affordable at under $28

Cons:

• Battery only (no solar backup) — bring fresh batteries
• 3x3 matrix limit (the Casio fx-991CW handles 4x4)
• Fewer total functions than Casio models (but includes everything the FE tests)

2. Casio fx-115ES Plus 2nd Edition — Best Budget

At $16.99, the Casio fx-115ES Plus 2nd Edition is the most affordable NCEES-approved calculator that still offers the advanced features FE candidates need. If you want matrix operations, equation solving, and numeric integration without spending $28, this is your calculator.

Why budget-conscious candidates choose it: The fx-115ES Plus does everything the TI-36X Pro does at 60% of the price. It has matrix and vector operations, an equation solver (up to 3 unknowns for simultaneous equations), complex number support, numeric integration, and 280+ functions total. The Natural Textbook Display shows equations exactly as they appear in textbooks and on the FE reference handbook, which reduces transcription errors.

Key specs for FE:

• 280+ functions with Natural Textbook Display
• Matrix operations up to 3x3
• Equation solver (simultaneous equations with 2-3 unknowns)
• Complex number arithmetic
• Numeric integration and differentiation
• Statistics with regression
• Table function for evaluating expressions at multiple values
• Solar + battery dual power

The solar advantage: The Casio fx-115ES Plus runs on solar power with battery backup. This means your calculator will never die during the exam — even if the battery is completely dead, ambient light keeps it running. On a 5-hour exam where you cannot bring a backup calculator, this is genuine peace of mind.

Pros:

• Most affordable advanced calculator for FE (~$17)
• Solar + battery dual power — impossible to run out of power
• Natural Textbook Display matches FE reference handbook notation
• 280+ functions including matrices, equation solver, calculus
• Simultaneous equation solver (2-3 unknowns) — TI-36X Pro lacks this

Cons:

• Fewer FE-specific tutorials compared to TI-36X Pro
• Two-line display (vs TI-36X Pro four-line) — less context visible
• Keypad layout takes adjustment if you are used to TI calculators
• Navigation through menus can be slower for some operations

3. Casio fx-991CW — Best for Power Users (Newest Model)

The Casio fx-991CW is the newest and most powerful NCEES-approved calculator on the market. With 540+ functions, 4x4 matrix operations, a high-resolution 4-tone display, and a spreadsheet-style data viewer, it is objectively the most capable scientific calculator you can bring to the FE exam.

What makes it special: The fx-991CW handles 4x4 matrices — the only NCEES-approved calculator to do so. While most FE problems involve 2x2 or 3x3 systems, having 4x4 capability provides a safety net for the occasional larger system. The high-resolution display is noticeably sharper than older models, reducing eye strain during a 5+ hour exam. And the spreadsheet-style data viewing mode lets you organize calculations in a table format that some candidates find more intuitive.

Key specs for FE:

• 540+ functions (most of any NCEES-approved model)
• High-resolution 4-tone display with enhanced visibility
• Matrix operations up to 4x4 (unique among approved models)
• Equation solver with simultaneous equations (up to 4 unknowns)
• Numeric calculus (integration, differentiation, summation)
• QR code feature links to Casio web tools for visualization
• Spreadsheet-style data viewing (up to 5 columns x 45 rows)
• Solar + battery dual power
• Complex numbers, vectors, base-N calculations, ratio

Pros:

• Most functions of any NCEES-approved calculator (540+)
• Only approved model with 4x4 matrix operations
• High-resolution display reduces eye strain on long exam
• Solar + battery dual power — zero battery anxiety
• Equation solver handles up to 4 simultaneous unknowns
• Modern interface with intuitive menu navigation

Cons:

• Fewest FE-specific tutorials — most prep courses do not teach its keystrokes
• New interface differs significantly from older Casio models
• Menu-driven approach can be slower if you are used to direct-access keys
• QR code feature is irrelevant for the exam

4. TI-30XIIS — Good Alternative (Basic)

The TI-30XIIS is a straightforward, no-frills scientific calculator that gets the job done if you do not need matrix operations or equation solving. At $17.99 with solar + battery power, it is reliable and affordable — but it is a basic tool for an advanced exam.

Who should consider it: Candidates who are supremely confident in their ability to solve matrices by hand, do not need an equation solver, and want a simple calculator they already know from college coursework. The TI-30XIIS is the calculator most engineering students used in freshman and sophomore courses, so the familiarity factor is real.

Key specs for FE:

• 2-line display (entry + result)
• Fraction/decimal conversion
• One and two variable statistics with regression
• Trigonometric functions, logarithms, exponentials
• Solar + battery dual power
• Basic scientific functions

What it lacks: No matrix operations. No equation solver. No numeric integration. No complex number mode. No unit conversions. Every one of these missing features means more manual calculation time on the FE exam. For 110 questions in 5 hours 20 minutes, those extra minutes add up.

Pros:

• Extremely familiar — most engineering students used this in college
• Solar + battery powered — reliable all-day
• Simple and fast for basic calculations
• Affordable at ~$18
• Nothing to configure or learn — you already know it

Cons:

• No matrix operations — must solve systems by hand
• No equation solver — must rearrange and solve manually
• No numeric integration or differentiation
• No complex number mode
• No unit conversions
• Significantly slower for FE-level problems than advanced models

5. Casio fx-991ES Plus 2nd Edition — Alternative Casio

The Casio fx-991ES Plus sits between the fx-115ES Plus and the fx-991CW in terms of capability and price. With 417 functions and the same Natural Textbook Display found in the fx-115 series, it is a solid choice for candidates who want more power than the fx-115ES Plus without the learning curve of the fx-991CW's new interface.

What distinguishes it: The fx-991ES Plus has a redesigned keypad with color-coded key groupings that make it easier to find functions quickly during the exam. It shares the same calculation engine as the fx-115ES Plus but adds extra statistical distributions, additional equation solving modes, and more extensive base-N calculations.

Key specs for FE:

• 417 functions with Natural Textbook Display
• Matrix operations up to 3x3
• Equation solver (simultaneous and polynomial)
• Complex number arithmetic
• Numeric integration and differentiation
• Statistics with probability distributions
• Solar + battery dual power
• Color-coded keypad for faster function access

Pros:

• 417 functions — more than fx-115ES Plus, well-organized
• Natural Textbook Display matches FE reference handbook notation
• Color-coded keypad reduces hunt-and-peck during exam
• Solar + battery — reliable power
• Non-programmable — fully NCEES compliant with no risk of rejection

Cons:

• More expensive than fx-115ES Plus ($28.94 vs $16.99) with similar core features
• Fewer tutorials than TI-36X Pro
• 3x3 matrix limit (same as most approved models)
• May be harder to find in local stores

The On-Screen TI-30XS MultiView: Your Built-In Backup

One of the most important — and often overlooked — features of the FE exam is the digital TI-30XS MultiView calculator provided on screen by NCEES. This on-screen calculator is available throughout the entire exam, regardless of what physical calculator you bring.

What it can do:

• Basic scientific calculations (trig, logs, exponents)
• Four-line MultiView display (same as the physical version)
• Fraction/decimal conversion
• Statistics with regression
• Unit conversions (limited set)
• Table function

What it cannot do:

• Matrix operations
• Equation solving
• Numeric integration or differentiation
• Complex number arithmetic
• Vector operations

How to use it strategically:

1. As a backup — if your physical calculator malfunctions, the on-screen version handles basic calculations
2. As a second screen — some candidates use the on-screen calculator for quick arithmetic while keeping their physical calculator set up for a complex matrix or equation problem
3. For verification — quickly double-check a calculation on the on-screen version while your physical calculator retains your working values

Pro tip: Spend 15 minutes practicing with the NCEES on-screen calculator before exam day. NCEES provides a practice exam environment where you can try the digital calculator. Knowing how it works — even if you never need it — eliminates one source of exam-day anxiety.

Which Calculator Should You Choose?

Use this decision framework to pick the right calculator for your situation:

Are you starting from scratch with no calculator preference? -> Get the TI-36X Pro ($27.95). It is the industry standard for the FE exam with the widest tutorial support. You will never struggle to find a how-to video.

Is budget your top priority? -> Get the Casio fx-115ES Plus 2nd Edition ($16.99). It has every advanced feature the FE tests — matrices, equation solver, numeric calculus — at the lowest price.

Do you want the most powerful calculator allowed? -> Get the Casio fx-991CW ($20.99). Its 540+ functions and 4x4 matrix capability exceed everything else on the approved list, at a surprisingly reasonable price.

Did you already use a Casio in college? -> Stick with Casio. The fx-115ES Plus or fx-991ES Plus share similar layouts. Muscle memory under exam pressure is more valuable than any feature advantage.

Did you already use a TI-30XIIS in college? -> Consider upgrading to the TI-36X Pro. The keypad layout is similar enough that the transition is quick, but you gain matrix operations, equation solving, and a four-line display. If you have less than 2 weeks before the exam, stick with the TI-30XIIS rather than learning a new calculator.

Our overall recommendation: For the vast majority of FE candidates, the TI-36X Pro at $27.95 is the best choice. It has the right features, the best tutorial ecosystem, and the widest community support. The Casio fx-115ES Plus 2nd Edition at $16.99 is the best value if budget matters.

Essential Calculator Setup for FE Exam Day

Unlike financial calculator exams, the FE exam does not clear your calculator memory. However, you should still know how to configure your calculator optimally before the exam starts.

TI-36X Pro Setup

1. Press MODE and ensure you are in DEG mode (not RAD or GRAD) — most FE problems use degrees
2. Set the display to FLOAT or a fixed number of decimal places as preferred
3. Familiarize yourself with the 2ND key access for matrix, vector, and equation solver modes
4. Practice switching between DEG and RAD modes quickly — some calculus and physics problems require radians

Casio fx-115ES Plus / fx-991ES Plus Setup

1. Press SHIFT → MODE → set angle unit to Deg
2. Ensure display format is set to MthIO (Math Input/Output) for natural textbook display
3. Practice navigating to Matrix, Equation, and Integration modes via the MODE menu
4. Confirm solar panel is unobstructed — clean the panel surface before exam day

Casio fx-991CW Setup

1. Access Settings → set angle unit to Degree
2. Set input/output format to MathI/MathO for natural display
3. Practice the menu-driven interface — the fx-991CW uses a different navigation system than older Casio models
4. Explore the Spreadsheet mode — it can help organize multi-step engineering calculations

Exam Day Calculator Checklist

Use this checklist the night before and morning of your FE exam:

• Calculator — confirm it is an NCEES-approved model (check the exact model name on the NCEES list)
• Fresh batteries installed — even if your calculator has solar power, install fresh batteries as a precaution
• Extra batteries in your bag — leave them in your locker at the testing center (not allowed in the testing room, but available at breaks)
• Angle mode set to degrees — the default for most FE problems
• Practice 5 minutes of calculator operations — matrices, equation solver, unit conversions — confirm everything works
• Clean the screen and keys — a clear display and responsive buttons reduce frustration
• Remove any stickers or unauthorized labels — keep your calculator clean and simple for proctor inspection
• Know how to access the on-screen TI-30XS — practice with the NCEES digital calculator at least once
• Set your calculator to the correct display mode — natural display for Casio, MultiView for TI

FE Exam Calculator Tips That Save Time

After talking to hundreds of FE candidates, these are the calculator strategies that consistently save the most time:

1. Use the equation solver instead of algebra

When a problem gives you a formula and asks you to solve for a middle variable, do not rearrange the equation by hand. Enter the formula into the equation solver, plug in the known values, and let the calculator solve for the unknown. This eliminates algebraic errors and is faster for complex formulas.

2. Solve systems of equations with matrices

The FE exam regularly tests systems of 2-3 linear equations. Instead of using substitution or elimination by hand, enter the coefficient matrix and solve using the calculator's matrix inverse or equation solver. A 3x3 system that takes 3-4 minutes by hand takes 30 seconds on the TI-36X Pro or Casio fx-115ES Plus.

3. Use the table function for trial-and-error problems

Some FE problems are most efficiently solved by testing values. The table function (available on TI-36X Pro and Casio models) lets you evaluate an expression at multiple input values simultaneously, making trial-and-error problems fast.

4. Memorize the shortcut keys for your model

Every calculator has shortcuts that bypass menu navigation. On the TI-36X Pro, learn the direct-access keys for matrix, equation, and integration modes. On Casio models, memorize the MODE number for each function (e.g., MODE 6 for matrix on fx-115ES Plus). Shaving 5 seconds per function access across 110 questions saves 9+ minutes.

5. Use the ANS key for chained calculations

All approved models store the last result in an ANS (answer) variable. Instead of writing down intermediate results and re-entering them, use ANS to chain calculations. This is faster and eliminates transcription errors.

A Note on Discontinued HP Models

The HP 33s and HP 35s remain on the NCEES approved list but are both discontinued. If you already own one and are comfortable with it, you can use it on the FE exam. The HP 35s in particular is a capable RPN scientific calculator with equation solving and matrix operations.

However, do not buy a discontinued HP calculator for the FE exam. Prices on the secondary market are inflated ($100+ for models that originally cost $50), quality is unpredictable for used units, and you will find almost zero FE-specific tutorial support. The TI-36X Pro at $27.95 is a far better investment.

Free FE Exam Prep Resources

The right calculator is only one piece of FE exam success. Pair it with solid study materials:

• Free FE Exam Study Guide — Complete content coverage across all FE knowledge areas including math, statics, dynamics, thermodynamics, fluid mechanics, and engineering economics
• Free FE Practice Questions — Unlimited attempts with detailed answer explanations
• AI Tutor — 10 free questions per day — ask it to walk you through calculator keystrokes for any FE problem
• FE Exam Reference Handbook — The official NCEES reference provided during the exam (free PDF download)

The AI tutor is especially useful for calculator practice. Ask it questions like "Walk me through how to solve a 3x3 system of equations on the TI-36X Pro" or "How do I use numeric integration on the Casio fx-115ES Plus for a thermodynamics problem?" and it will give you step-by-step keystroke instructions.

Final Verdict

For most FE candidates, the TI-36X Pro ($27.95) is the best choice. It is the most recommended calculator in the FE prep ecosystem, has the widest tutorial support, and offers the exact feature set — equation solver, matrices, numeric calculus, unit conversions — that FE problems demand. At under $28, it is also reasonably priced.

If budget is your top concern, the Casio fx-115ES Plus 2nd Edition ($16.99) delivers nearly identical capability at 60% of the cost, with the added benefit of solar + battery dual power.

If you want the most powerful option available, the Casio fx-991CW ($20.99) has 540+ functions and 4x4 matrix support — but be prepared to find your own tutorials since FE prep resources rarely cover it.

Whichever calculator you choose, the most important thing is to buy it early and practice with it daily. Use it for every homework problem, every practice exam, and every study session. By exam day, operating your calculator should be pure muscle memory — you should be thinking about the engineering problem, not the keystrokes.

free FE study guideFree exam prep with practice questions & AI tutor