Casio fx-991ES Plus vs fx-991EX ClassWiz — Detailed Comparison
The Casio fx-991ES Plus and fx-991EX ClassWiz are the two most popular scientific calculators in Indian and international student markets. They look similar, share many functions, but differ in important ways under the hood. Here is a feature-by-feature comparison to help you choose.
Feature set overview
fx-991ES Plus 2nd Edition: 417 functions, natural V.P.A.M. display, single-line cursor history. fx-991EX ClassWiz: 552 functions, higher-resolution dot-matrix display, multi-line history with scroll-back, QR-code answer sharing with the ClassWiz app. Both handle trig, log, exp, factorial, nCr, nPr, complex numbers, matrix operations up to 4×4, statistics, and base-N conversions. The ClassWiz adds spreadsheet mode and distribution-function probability tables.
Display quality
fx-991ES Plus uses a 31×96-pixel dot matrix. fx-991EX uses a 192×63-pixel dot matrix — about four times the resolution. The difference is most visible on fractions, surds, and integrals — the ClassWiz renders √(x² + 1)/(2x) cleanly, while the ES Plus compresses it. Both display two lines (expression and result) but the ClassWiz lets you scroll back through previous calculations.
Speed and processor
ClassWiz is about twice as fast for matrix and equation operations — Casio's published spec is 'up to 4× faster' but real-world tests put it at 2–3× faster. For one-off calculations, the difference is imperceptible. For repeated equation-solver or table-mode work, ClassWiz feels noticeably snappier.
Price comparison (India, 2026)
fx-991ES Plus 2nd Edition: ₹1,150–₹1,400 from Amazon, Flipkart, and authorised Casio retailers. fx-991EX ClassWiz: ₹2,200–₹2,800. The ₹1,000+ price difference reflects the ClassWiz's newer architecture, faster processor, and higher-resolution display. Both come with manufacturer warranty in India.
Which to buy in 2026
For a first scientific calculator at school level (Class 9–10): fx-991ES Plus is excellent value. For JEE/NEET preparation or engineering coursework: fx-991EX ClassWiz justifies the extra cost — faster, better display, more functions. If you are deciding between a new ClassWiz and a second-hand ES Plus, take the new one — battery degradation and button wear matter on used calculators.
What neither model does
Neither calculator is allowed in JEE Main, JEE Advanced, NEET, or most Indian competitive exams. Both are for home and classroom use only. Neither does symbolic algebra (no integration of f(x) symbolically — only numerical), 3D graphing, or programming. For those features, look at the fx-CG50 (graphing) or Classpad II (CAS) — different category, different price (₹12,000–₹15,000).
Frequently asked questions
Is the fx-991EX ClassWiz worth the extra money over the fx-991ES Plus?
For serious JEE, NEET, or engineering work — yes. The faster processor, better display, and 135 extra functions help on long study sessions. For school-level use only, the fx-991ES Plus does everything needed at lower cost. Choose ClassWiz if you expect heavy daily use for two or more years.
How many functions does each calculator have?
fx-991ES Plus 2nd Edition: 417 functions. fx-991EX ClassWiz: 552 functions. The difference covers spreadsheet mode, probability distributions, QR-code sharing, and additional matrix operations on the ClassWiz. For most students, the function set differences are less important than the speed and display improvements.
Do these calculators come with a warranty in India?
Yes. Both are sold through Casio's authorised Indian distribution network with a 3-year manufacturer warranty. Buy from Amazon (Casio India seller), Flipkart (authorised), or large electronics chains. Avoid grey-market sellers — warranties may not honour.
Can the ClassWiz scan QR codes?
The ClassWiz generates QR codes containing your calculation result, which you scan with the ClassWiz smartphone app to see graphs and visualisations. It does not scan QR codes from external sources. The feature is useful for visualising functions and tables that the calculator screen cannot show clearly.
Which calculator do most students in India actually use?
Among medical and engineering aspirants in 2024–2026, the fx-991ES Plus 2nd Edition remains the most common choice (about 55% market share among JEE/NEET candidates). The fx-991EX ClassWiz sits second (about 30%). The remaining 15% mix Texas Instruments models and budget alternatives.