NCEES-approved calculators for the PE exam (2026)

Last updated: July 2026, checked against the NCEES calculator policy and the May 2026 NCEES Examinee Guide. NCEES updates both periodically — always confirm the official NCEES calculator policy for your exam year before you buy or test.

NCEES allows only a short list of calculator models in the exam room, and "close enough" does not count: if your exact model isn't covered, it isn't allowed. Here's the current list, the test you can run on your own calculator in thirty seconds, the rules that trip people up, and what actually happens if yours dies mid-exam.

The approved models (2026)

NCEES currently permits these families:

Brand	Approved models
Casio	All fx-115 and fx-991 models
Hewlett Packard	HP 33s and HP 35s (only these two)
Texas Instruments	All TI-30X and TI-36X models

The thirty-second test on the calculator you already own

NCEES states the rule as a model-name test: a Casio's name must contain fx-115 or fx-991, and a Texas Instruments' name must contain TI-30X or TI-36X. So:

• Find the model name printed on the faceplate — usually along the top edge, above the display. The photographs further down show where to look on each brand.
• If it contains one of those four strings, the model family is approved. Suffixes are fine: ES, PLUS, 2nd Edition, MultiView, Pro, X — none of them break the rule.
• If it doesn't contain one of those strings, it isn't approved. A TI-84 is not a TI-36X. An fx-991 is approved; an fx-991-lookalike with a different number is not.

HP is the exception: only the 33s and 35s specifically, not a family.

Which approved calculator should you pick?

All allowed models will get you through the exam — but they're not identical. Popular choices and why:

Casio fx-115ES
name on the top edge

TI-36X Pro
name across the top

HP 35s
name at the top left

• Casio fx-115ES PLUS — the most common PE pick. Natural "textbook" display, a built-in equation solver, numeric integration, and complex numbers — handy for the messy arithmetic the exam throws at you.

• Texas Instruments TI-36X Pro — multi-line display, solver, and good for engineers who already use TI; very similar capability to the fx-115.

• HP 35s — favored by RPN users and those who want a programmable-feeling workflow within the rules; steeper learning curve, so only if you already think in RPN.

The real rule: pick one and master it. Speed comes from keystroke familiarity, not features — whichever model you practice with for months is the right one.

Buying one

These are ordinary consumer scientific calculators, stocked by general retailers and office- and school-supply stores. Two things worth knowing:

• Buy on the model name, not the listing title. Run the thirty-second test above against the model printed on the product itself, not against a seller's description. Listings that lean on phrases like "engineering exam approved" are marketing, not the policy.
• Buy early, not the week before. The calculator is only worth what your fingers know about it. Every month you drill with it is a month of keystrokes you don't have to think about on exam day.

If a listing is priced far above what a mainstream scientific calculator normally costs, you're on a marked-up listing, not a special exam model — there is no such thing.

The rules that catch people out

• One calculator goes into the testing room. NCEES allows one approved calculator at your seat. Spare calculators stay with your personal belongings — the locker, not your desk.
• The cover doesn't come with you. The permitted-items list specifies the calculator without its cover, so plan to leave the case behind at check-in.
• Exact model families only. A newer or similar-looking version that doesn't pass the model-name test is not allowed — don't assume.
• Fresh batteries before exam day. Since your spare is in a locker, batteries are your real insurance, not the second calculator.

If your calculator dies mid-exam

This is the scenario candidates plan for wrongly, so it's worth being precise.

Your spare is not reachable. It's with your personal belongings outside the testing room. Going to get it is not a quiet thirty-second fix.

You are not left with nothing. The NCEES Examinee Guide states that a TI-30XS can be accessed on-screen during the exam. That's a genuine safety net, and most candidates don't know it exists.

But it won't be your calculator. Whatever you've spent months drilling on — the solver, the memory keys, the muscle memory — none of that transfers to a different model under a running clock. Treat the on-screen calculator as the thing that stops a dead battery from ending your exam, not as a plan.

The practical takeaway is unglamorous: new batteries in the week before the exam. That single habit removes the failure mode entirely.

How to use it for free points

• Let the Handbook do the conversions. The on-screen NCEES Reference Handbook has conversion and property tables — reach for those before keying a long conversion by hand. (How to use the Mechanical Handbook.)
• Know your high-frequency keystrokes cold — the equation solver, unit work, switching degree/radian, complex numbers, memory store/recall.
• Use memory store for constants you reuse across a problem instead of re-keying them.
• Clear between problems. Press AC/CLEAR before each new problem — especially after solver, matrix, or complex-number work — so a leftover value doesn't quietly wreck an answer.
• Practice the way you'll test: every practice problem with your approved calculator and the Handbook open. That combined workflow is the muscle memory the exam actually rewards.

Common mistakes

• Buying a model "like" an approved one (e.g., a graphing TI) and discovering at the door it's banned.
• Showing up with a brand-new calculator you haven't drilled with — fumbling keystrokes under the clock.
• Counting on a locker spare as a mid-exam fix. It isn't one.
• Leaving degree/radian mode set wrong and not noticing until answers are off.