Best overall: TI-84 Plus CE — approved for every exam (ACT, SAT, AP, FE). The one calculator that works from high school through your engineering degree.
Best value: Casio FX-991CW ($22) — 552 functions, FE exam approved. Covers freshman and sophomore engineering without paying $100+.
Best for advanced engineering: TI-Nspire CX II CAS — full CAS (symbolic algebra) and still FE exam legal. The only model that does both.
Best for CFA / finance: BA II Plus Professional — the only TI model the CFA Institute approves.
The TI-84 Plus CE dominates engineering classrooms because it passes every standardized exam — but it runs on a processor from the 1980s. In 2026, the Casio FX-991CW gives you more calculating power at a fifth of the price. This guide maps each model to your actual use case.
Best Calculators 2026 — Quick Comparison
| Model | Type | CAS | ACT / SAT | FE Exam | Price |
|---|---|---|---|---|---|
| TI-84 Plus CE Best Overall | Graphing | No | ✓ Yes | ✓ Yes | ~$119 |
| Casio FX-991CW Best Value | Scientific | Partial | ✓ Yes | ✓ Yes | ~$22 |
| TI-Nspire CX II CAS Best CAS | CAS Graphing | Full | ✗ No | ✓ Yes | ~$165 |
| HP Prime G2 | CAS Graphing | Full | ⚠ Check | ⚠ Check | ~$149 |
| Casio FX-9750GIII | Graphing | No | ✓ Yes | ✓ Yes | ~$49 |
| BA II Plus Professional | Financial | No | N/A | N/A | ~$65 |
Reviews: Top 4 Engineering Calculators
Every exam. Every professor. Every engineering course. The TI-84 Plus CE is the only calculator you can buy once and never worry about being turned away at the door.
The 2026 value unlock: Python scripting. You can automate repetitive calculations directly on the device — no other $119 calculator does this with the same universal exam clearance. Where it falls short: no symbolic algebra (CAS). By year 3 of an engineering degree, that starts to matter.
✓ Pros
- Approved: ACT, SAT, AP, and FE exam
- Python scripting built in
- Rechargeable battery
- Largest tutorial library of any calculator
✗ Cons
- No CAS — can’t solve symbolic algebra
- Z80 CPU from 1983 — slow on matrices
- $119 for outdated hardware
At $22, the Casio FX-991CW does things that cost $149 three years ago. Spreadsheet mode, QR-code graphing via your phone, vector operations — all in a calculator cheaper than a textbook chapter.
The killer feature: press Shift+Graph, scan the QR code, and the graph renders in full color on the free Casio EDU+ app. The spreadsheet mode (5×45 cells) handles iterative calculations like Manning’s equation that the TI-84 can’t touch without programming. Buy this regardless of what else you own — it’s a $22 backup that saves you on exam morning.
✓ Pros
- $22 — cheapest on this list by far
- 552 functions incl. spreadsheet + vector
- 3-year battery on a single AAA
- ACT, SAT, FE exam approved
✗ Cons
- No standalone graphing screen
- QR graph requires phone (banned in exams)
- No Python or programming
The only full CAS graphing calculator that’s still legal on the FE exam. That combination — symbolic algebra plus professional exam clearance — exists nowhere else at this price.
CAS means it solves symbolically: give it an integral, it returns the exact closed-form answer instead of a decimal. This matters in Differential Equations, Control Systems, and Circuits. Python 3.6 scripting is included. 100MB of storage lets you keep an entire semester of notes and programs on the device.
✓ Pros
- Full CAS + FE exam approved — unique combination
- Python 3.6 scripting
- 100MB storage — entire semester on one device
- 3D graphing for Multivariable Calc
✗ Cons
- Banned from ACT and SAT
- Most expensive at ~$165
- Steeper learning curve than TI-84
The HP Prime G2 runs an ARM Cortex-A7 at 500MHz with 256MB RAM. It processes eigenvalue calculations and Laplace transforms in milliseconds. This is what engineers buy after they graduate.
The CAS engine solves symbolic integrals, differential equations, and matrix operations analytically — instantly. The 3.5-inch color touchscreen handles 3D graphing natively. The one catch: CAS status disqualifies it from the ACT and SAT. Verify your exam rules before relying on it as your only calculator.
✓ Pros
- Full CAS — exact symbolic answers
- 256MB RAM — fastest on this list
- Touchscreen + physical keyboard
- 3D graphing built in
✗ Cons
- Banned from ACT and SAT
- FE exam eligibility — verify before buying
- Smaller community than TI
Calculator Allowed on ACT / SAT / AP / FE Exam
Wrong calculator on exam day means disqualification. This table reflects 2026 official rules — confirm with the exam body before test day.
| Calculator | ACT | SAT | AP Calc | FE / PE Exam | CFA |
|---|---|---|---|---|---|
| TI-84 Plus CE | ✓ | ✓ | ✓ | ✓ | ✗ |
| Casio FX-991CW | ✓ | ✓ | ✓ | ✓ | ✗ |
| TI-Nspire CX II CAS | ✗ | ✗ | ✗ | ✓ | ✗ |
| HP Prime G2 | ⚠ | ✗ | ⚠ | ⚠ | ✗ |
| Casio FX-9750GIII | ✓ | ✓ | ✓ | ✓ | ✗ |
| BA II Plus Professional | ✗ | ✗ | ✗ | ✗ | ✓ |
More Engineering Tools
Best Lab Scales for Engineering 2026
0.001g precision scales for chemistry and engineering labs — all under $100.
Best CAD Software for Engineering 2026
Fusion 360, SolidWorks, FreeCAD — which tool to learn and which gets you hired.
Gallons to Liters Converter
Instant volume conversion for engineering, lab, and field work.
Liters to Gallons Calculator
US and Imperial volume — useful for fluid system specs and material data sheets.
Frequently Asked Questions
2nd → + → 7 → 1 → 2. Clears variables and programs. Full factory reset: Hold DEL while pressing ON. Clears everything including the archive.Our Verdict
The TI-84 Plus CE is the safest buy for years 1–4 because it passes every exam you’ll face. If you’re past sophomore year heading into Differential Equations or Control Systems, upgrade to the TI-Nspire CX II CAS — it’s the only CAS calculator that stays FE exam legal.
The Casio FX-991CW at $22 belongs in every student’s bag regardless. A dead Li-ion battery on exam morning is a real failure mode. This is your backup that costs less than dinner.