Is the Casio fx-115ES Plus approved for the FE exam?

NCEES does not publish a list of individual approved calculators. It publishes a rule by model prefix, and for 2026 examinations the approved Casio models are those beginning fx-115. The fx-115ES Plus 2nd Edition is one of them.

That phrasing matters more than it looks. A prefix rule means the specific edition you buy is less important than the family it belongs to — but it also means the rule can change between publication and your seat date. Check the current policy against the day you actually sit the exam. That is a thirty-second check, and it is the only part of this decision that can go wrong after purchase.

Casio's current catalogue lists both the fx-115ES PLUS 2nd Edition, model FX-115ESPLUS-2, and the fx-115ES PLUS B 2nd Edition, model FX-115ESPLUSB-2. They are different products. The first is solar-and-battery; the B model runs on a single AAA cell.

Both begin fx-115, so both sit inside the prefix rule. The difference is power, not eligibility — but if you have decided which one you want, the listing title is not always enough to tell them apart at a glance.

There is a reliable way to check from the photograph alone. The solar-and-battery model carries a visible solar panel above the display, and the words 2nd edition are printed on the face beside it. If you can see the panel in the product image, you are looking at the FX-115ESPLUS-2.

The reason a licensing body names calculators at all is to bar programmable and graphing models, which can carry stored formulas into an exam room. Casio describes this model as non-programmable and non-graphing, and that is precisely why it survives exam rules that eliminate more capable machines.

So the limitation is the qualification. A calculator that could do more would be a calculator you could not bring.

Casio lists natural textbook display, complex numbers, vectors, matrices, numerical differentiation and integration, equation and inequality solving, statistics, scientific constants and metric conversions. In practice that is the working set for algebra, trigonometry, statistics, numerical calculus, physics and chemistry.

Owner accounts run long. One reported using this exact edition for several years while teaching chemistry at a community college. Another said it carried them through every engineering mathematics and physics class they took. A University of Mississippi calculus-based physics syllabus recommends this exact model by name to students buying new — which is an institution choosing it, not a manufacturer promoting it.

Worthivo has not tested this calculator. Those are published accounts and published specifications, and the review linked below shows every source behind them.

Matrices are capped at three by three. Numerical work is slower than newer platforms. One owner reproduced a Math ERROR raising a general complex number to the fourth power while cubing the same number worked, and others in that thread described polar-form workarounds.

None of that touches ordinary scientific calculation, and none of it affects exam eligibility. But if your work routinely sits past those edges, buy a different class of tool — you will not be able to bring it into the exam room either way, which means you may need both.