You’ve spent months drilling quadratic equations and memorizing how to find the area of a sector. Then, a week before the test, you realize your trusty calculator might actually be "illegal" in the eyes of the College Board. It’s a mild panic that hits almost every student. Honestly, the rules for calculators allowed on SAT have changed more than you’d think lately, especially with the 2025-2026 update that finally banned CAS (Computer Algebra System) models.
The digital SAT is a different beast. You aren’t just sitting there with a No. 2 pencil and a bubble sheet anymore. Now, everything happens inside the Bluebook app. This shift has changed the "calculator game" entirely. Some kids show up with three backups, while others realize the built-in tool is actually better than the hunk of plastic in their backpack.
The Massive 2025 Policy Shift: No More CAS
For years, students used the TI-Nspire CX CAS like a secret weapon. It could solve for "x" symbolically, meaning you didn't even have to do the algebra. You just typed the equation and—boom—there was the answer. Well, the College Board finally put their foot down. Starting in late 2025, any calculator with CAS functionality is officially banned.
If your calculator has the letters "CAS" printed anywhere on the front, leave it at home. Seriously. If a proctor sees you with a TI-89 or a TI-Nspire CX II CAS, they can cancel your scores on the spot. It sounds harsh, but they’re trying to level the playing field so the kid with the $170 "super-calculator" doesn't have an unfair advantage over the kid with a standard TI-84.
What about scientific calculators?
There’s been some weird misinformation floating around online saying scientific calculators are banned. That’s just wrong. Most scientific calculators—like the TI-30XS or the Casio fx-300ES—are perfectly fine. They don't have the "brain" to solve algebra for you, so they aren't considered a threat to the test's integrity. Just make sure it doesn't have a QWERTY keyboard (the kind that looks like a laptop) or a power cord.
The Approved List: What You Can Actually Bring
So, what are the calculators allowed on SAT right now? Basically, most graphing calculators that aren't on the "naughty list" are fair game. The TI-84 Plus CE remains the king of the testing room. It’s reliable, the battery lasts forever, and it doesn't have CAS, so you’re safe.
Here is the breakdown of the heavy hitters that are still 100% legal:
- Texas Instruments: TI-84 Plus, TI-84 Plus CE, TI-Nspire CX (non-CAS), TI-83 Plus.
- Casio: FX-9750 series, FX-9860 series, and the newer FX-CG50 (Prizm).
- HP: HP 39gs, HP 40gs (but NOT the HP Prime unless it's in a specific non-CAS mode, though it's safer to avoid it).
- NumWorks: The sleek white graphing calculator that’s become popular recently is also allowed.
Wait, check your display. If your calculator has characters that are an inch high or a screen that tilts up so the person behind you can see your work, the proctor might move you to the back of the room. It’s not a ban, but it’s definitely an awkward way to start your morning.
The Built-In Secret: Desmos is Already There
Here is the part most people overlook: You don’t actually need to bring a handheld calculator anymore. Every student taking the digital SAT has access to a built-in graphing calculator right inside the Bluebook app. It’s a version of Desmos, and frankly, it’s incredible.
It’s fast. You can type in a system of equations, and it will literally show you the intersection point. You just tap it with your mouse or finger, and the coordinates pop up. No more "2nd + Trace + 5" like on the old TI-84s. If you haven't practiced with the Bluebook Desmos, you are leaving points on the table.
But there’s a catch. Some students find it clunky to toggle between the question and the calculator window on a small laptop screen. That’s why many experts still recommend bringing a physical calculator as a "sidekick." You use the handheld for quick arithmetic—like $14 \times 12$—and use the on-screen Desmos for the heavy-duty graphing. It’s the best of both worlds.
Common Mistakes That Get Calculators Confiscated
I've seen it happen. A student brings a calculator they've used for three years in AP Calculus, only to have it taken away at the door. Usually, it's one of these three reasons:
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- The QWERTY Keyboard: If your calculator has a full "A-Z" keyboard like a computer, it's out. The College Board thinks you'll use it to type out and steal test questions.
- The Power Cord: You cannot plug your calculator into a wall. It must be battery-operated. If your TI-84 CE is dying, charge it the night before. You can't hunt for an outlet mid-test.
- Communication Capabilities: This is rare, but if you have an old calculator with infrared ports or anything that can "talk" to another device via Bluetooth or Wi-Fi, it’s a no-go. You’ll need to cover those infrared sensors with opaque tape (like duct tape) before you walk in.
Is the "Backup" Calculator Necessary?
Kinda.
The Bluebook app is stable, but technology is moody. If your laptop glitches or your handheld calculator runs out of juice, having a backup scientific calculator in your bag is a smart move. You’re allowed to have two calculators on your desk, but you can only use one at a time. Put the backup on the floor under your chair so it’s there if the primary one dies.
Actionable Next Steps for Test Day
Don't wait until Saturday morning to figure this out. Here is what you need to do right now to make sure your calculators allowed on SAT strategy is solid:
- Verify the CAS Status: Look at your calculator's screen when it turns on. If it says "CAS" or "Algebraic," it is banned.
- Update Your Handheld: If you’re using a TI-84 Plus CE, make sure you have the latest OS. Some older versions have "apps" that the College Board might find suspicious.
- Practice with Bluebook: Download the Bluebook app today. Run a practice test and specifically use the embedded Desmos calculator. Learn how to plot a circle and find intercepts. It’s a game-changer.
- Fresh Batteries/Full Charge: This sounds obvious, but you’d be surprised. Charge your calculator and your laptop. If your handheld uses AAA batteries, put a fresh 4-pack in your bag.
- Clear the Memory: Some proctors will ask you to reset your calculator memory before the test starts. Know how to do this ($2nd + Mem + 7 + 1 + 2$ on a TI) so you don't look flustered.
Knowing the rules isn't just about avoiding trouble; it's about confidence. When you know your gear is legal and you know how to use it, you can focus on the actual math instead of worrying if the proctor is staring at your TI-Nspire.