FE Exam Calculator Guide
Your calculator is one of only two tools you have on the FE exam (the other is the reference handbook). Knowing your calculator inside and out can save significant time and prevent errors. This guide covers approved models, essential functions, and speed techniques.
NCEES-Approved Calculators
NCEES maintains a list of approved calculators for the FE exam. As of the current exam cycle, the approved models include:
- Casio FX-115 and FX-991 series (various models)
- Hewlett Packard HP 33s and HP 35s
- Texas Instruments TI-30X and TI-36X series
Important rules:
- Only calculators on the approved list are allowed. No graphing calculators, no programmable calculators.
- You may bring up to two approved calculators.
- Calculator covers must be removed before the exam.
- Calculators are inspected at the testing center.
- Check the current approved list on the NCEES website, as it may be updated.
Choosing Your Calculator
If you do not already own an approved calculator, choose one and start practicing with it well before the exam. Key considerations:
- Two-line display: Shows your input on one line and the result on another. Helps you catch entry errors.
- Scientific functions: Trigonometric, logarithmic, exponential, and power functions are essential.
- Complex number mode: Useful for electrical engineering problems (AC circuit analysis).
- Statistics functions: Mean, standard deviation, and linear regression can save time on statistics problems.
- Equation solver: Some approved models have built-in equation solvers that can save time.
- Matrix operations: Some approved models can handle matrix multiplication, determinants, and inverse. Very useful for linear algebra problems.
Essential Functions to Master
Basic Operations
- Order of operations (how your calculator handles precedence)
- Parentheses for complex expressions
- Memory storage and recall (STO, RCL) for intermediate results
- Answer key (ANS) to use the previous result in the next calculation
Scientific Functions
- Trigonometric functions (sin, cos, tan) and their inverses
- Switching between degrees and radians mode (and knowing which you need)
- Natural logarithm (ln) and common logarithm (log)
- Exponential function (e^x) and power function (x^y)
- Square root and nth root
Engineering-Specific Functions
- Unit conversion features (if available on your model)
- Complex number calculations (for AC circuits: rectangular and polar forms)
- Matrix operations (for solving systems of equations)
- Statistics mode (for mean, standard deviation, regression)
- Numerical integration (if available)
Speed Techniques
Chain Calculations
Instead of writing down intermediate results and re-entering them, use the ANS key or memory functions to chain calculations. This reduces entry errors and saves time.
Example: To calculate P = gamma * h * A where gamma = 9810, h = 3.5, A = 2.0:
Type: 9810 * 3.5 * 2.0 = (result: 68,670)
Rather than calculating each multiplication separately and writing down intermediate results.
Memory Registers
Use memory registers (STO A, STO B, etc.) to store values you will use multiple times in a problem. This avoids re-entering complex numbers and reduces errors.
Example: In a problem where you use the Reynolds number multiple times, calculate Re once, store it in memory A, and recall it each time you need it.
Shortcut for Repeated Calculations
Many FE exam problems require the same formula with different inputs. After solving the first one, you can edit the previous entry (on most two-line calculators, use the up arrow to recall the last entry) and change just the values that differ.
Verifying Answers
- Order of magnitude check: Before accepting an answer, verify that it is reasonable. If a beam deflection calculation gives you 500 meters, something is wrong.
- Unit check: Mentally verify that your units work out correctly.
- Reverse calculation: If time allows, plug your answer back into the original equation to verify.
Common Calculator Mistakes
- Wrong angle mode: Forgetting to switch between degrees and radians. Always check before solving trigonometry problems.
- Missing parentheses: The expression 1/2*pi is not the same as 1/(2*pi). Use parentheses when the denominator has multiple terms.
- Sign errors: Particularly in problems involving negative numbers, powers, and logarithms.
- Overflow/underflow: Very large or very small numbers can cause calculator errors. Use engineering notation or adjust units to keep numbers manageable.
- Not clearing previous entries: Make sure you start each calculation fresh, especially in statistics mode where previous data points may still be stored.
Practice Recommendations
- Use your exam calculator for ALL practice problems. Do not practice with a different calculator or a phone calculator.
- Practice without looking at the calculator manual. On exam day, you will not have the manual.
- Time yourself on calculations. If a calculation takes more than 2 minutes, find a faster approach or practice more.
- Practice complex number operations if you are taking the FE Electrical or any exam that includes AC circuits.
- Practice matrix operations if your calculator supports them and your exam includes linear algebra.
Exam Day Calculator Checklist
- Bring two approved calculators (one as backup)
- Install fresh batteries in both calculators the week before the exam
- Remove calculator covers before entering the testing center
- Verify your calculator is in the correct angle mode (degrees for most engineering problems)
- Clear all stored memories and programs
Your calculator is a tool that amplifies your preparation. The more comfortable you are with it, the faster and more accurately you will solve problems on exam day. Start practicing with your approved calculator today.